Planning a group picnic is no picnic. Nonetheless there are times - and the Fourth of July ranks high among them - when a picnic seems to be absolutely the right choice for a social gathering.

I would not presume to dictate what should be served at a picnic and, as Nika Hazelton wrote in her book on the subject, "I also take it for granted that people know how to amuse themselves on picnics." But it can describe the one in which I participated last July 4th, present a list of items better remembered before leaving home that after arriving at the picnic site and offer some recipe suggestions.

One of the great charms of the picnic is that it is formless. Food and drink are essential, but what they are and how they are presented is as free of convention as a work of modern art. Gadget-loving America has snatched up picnic equipment innovations almost faster than inventors crank them out, so even the most frail and fragile foods can be transported in safety.

There is a school of thought, to which I subscribe, that frowns on practicing creative cookery in public out-of-doors. I don't mind eating an elegant morsel of duck or squab on a picnic, but let it be cooked ahead of time in the congenial surroundings of a well-equipped kitchen or no further afield than the backyard grill.

How ambitious the food and how fancy the accoutrements? That should depend on the gastronomic inclinations and sense of formality of the group. No one - child or adult - who hates pate de foie gras in a restaurant is likely to take a sudden shine to it when presented in a bucolic setting. No one - female or male - should exhaust himself preparing and packing a three-star meal if swimming or fireworks are going to absorb the group's attention most of the time. If fancy food is desired, parcel out the preparations.

For our Independence Day picnic last year, attended by about 40 persons, 10 cooks worked separately for the collective good and two or three others provided wine, beer and soft drinks. The composite menu included two chilled soups, a salmon spread, assorted raw vegetables, homemade bread, Japanese-style cold beef and rice, chicken, Chinese-style barbecued spareribs, macaroni and potato salads, a watermelon boat filled with balls of assorted fruit and brownies.

Some central direction is necessary in such an effort to obtain - by suggestion or negotiation - a balanced menu lest the picnic turn into a comparative tasting of potato salads, and to run a checklist on essential support materials.

In no particular order, it should include: tablecloth(s), napkins, eating and serving utensils, glasses, paper towels, trash bags, ice, bottle opener, can opener, paring and slicing knives, a small cutting board, salt and pepper and drinking water. Chairs and cushions or straw mats and a folding card table might be in order.

Packing food properly is half the challenge. All sorts and shapes of containers are available and others can easily be jury-rigged. It is important that food be packed firmly so it won't slide about. Liquids - including salad dressings - should be in screw-top jars (close tightly). As a further safeguard, pack the jars in plastic bags.

Carve birds at home, but slice breads, cheeses and meat on location. Bake breads, pates or meatloafs in light pans rather than heavy molds and transport them in the pans. Keep hot foods warm and cold foods well chilled to avoid bacterial contamination. Commercial mayonnaise is well stabilized against spoilage, so don't be afraid to use it. But keep salads and sandwiches away from the sun. In fact, think ahead to the site when packing the picnic. If the food won't be under cover and will be accessible to bugs, insects and any tantrum Mother Nature may throw, you shouldn't plan to unveil the entire spread at once. Serve the food course by course.

A final word of warning. Don't become too ambitious. Someone once pointed out - wisely - that the proper setting for a haute cuisine picnic is at a table in a restaurant that serves food in an outdoor garden. SALAD OF TOMATOES

(4 to 6 servings) 2 large tomatoes 1 cucumber 1/4 cup chopped or slivered almonds 1/2 teaspoon Dijon-style mustard 1/4 teaspoon thyme 1/4 teaspoon celery seed 1 shallot or scallion, chopped fine 1/4 teaspoon ginger 1/4 cup olive oil 1/4 cup lemon juice 1 tablespoon chopped parsley (optional) 1/4 cup chopped or slivered almonds Salt and pepper

Immerse tomatoes in hot water for 10 to 15 seconds; peel and slice. Peel and slice the cucumber.

In a salad bowl combine the mustard, thyme, celery seed, shallot and ginger. And several grinds of pepper. Slowly add the oil, stirring with a fork or wisk until it reaches a mayonnaise consistency. Stir in the lemon juice. Adjust oil or lemon to taste.

Toss the tomato and cucumber slices with the sauce. Chill.

Just before serving add salt to taste and toss once more. Top with almonds and chopped parsley and serve. MELISSA'S SUNSHINE ICE TEA

(Makes about 1/2 gallon)

Fill a 1/2-gallon glass container nearly full with cold water. Put seven regular tea bags, 3 rose hips and 2 mint tea bags into the glass jar. Leave the tags hanging over the edge of the jar, seal with a lid and place in the sun outdoors or on a window ledge. At sunset bring in the jar, take out the tea bags and place in the refrigerator. TAPANADE 1 can (7 ounces) tuna fish 15 to 20 black olives, pitted 4 tablespoons capers 2 cans (2 ounces size) anchovy fillets 2 cloves garlic 2 lemons 2 tablespoons cognac 1/2 cup olive oil Freshly ground pepper

In a blender of food processor mix the tuna fish, oilves, capers, anchovy fillets, garlic and juice from the lemons. Using a low speed, slowly pour the olive oil into the blender. When a mayonnaise consistency has been reached, add the cognac and pepper. Correct seasoning and consistency with more cognac, pepper or some lemon juice. Note: This sauce can be stored in the refrigerator but should be served at room temperature on cold fish, meat or eggs. BEANS IN OIL (4 to 6 servings) 1/2 pound dried white beans Bay leaf, thyme, onion slices and whole peppercorns 1/2 cup oil (olive, salad or a mixture of the two) 2 tablespoons wine vinegar 1/2 tablespoon Dijon mustard 3 tablespoons chopped shallots or onion 2 tablespoons chopped parsley 1 tablespoon fines herbes or 1 teaspoon thyme, 1 teaspoon basil 1/2 teaspoon dill weed (optional)

Prepare the beans by directions on the package. Add a bay leaf, thyme and several slices of onion to the cooking water along with 8 to 10 peppercorns.

In a glass bowl mix the mustard, shallots, parsley, fines herbes, pepper. Gradually add the oil and vinegar, beating all together well and adjusting to taste with vinegar and salt. (The dressing should be mild, with less vinegar than a salad dressing.)

Toss warm beans with the dressing until well coated. Cool and store in refrigerator until shortly before serving. Just before serving correct seasoning with salt and pepper, add a bit of fresh oil if needed, toss again and serve topped with additional chopped parsley. PLATTER OF MARINATED VEGETABLES

Marinade: 3 cups chicken or veal stock 1 cup dry white wine 1 cup olive or vegetable oil 1/2 cup lemon juice 6 sprigs parsley 1 teaspoon thyme 2 cloves garlic, crushed 10 peppercorns, bruised 10 coriander seeds, bruised 1 teaspoon salt

Vegetables: 24 white onions 1 pound zucchini, sliced in 1/2-inch rounds 3 green peppers, cut into 1/2-inch strips 1/2 pound green beans 2 lemons, sliced, for garnish 2 tablespoons chopped parsley for garnish

Combine ingredients of the marinade in an enameled or stainless-steel pot. Bring to a boil and simmer, partly covered, for 45 minutes.

Strain the marinade and return to the pot. It should be somewhat over-seasoned. Add the onions and cook for 20 minutes, or until tender, with the not covered. Remove the onions to a bowl with a slotted spoon.

Add the zucchini and squash and cook for 10 minutes uncovered or until tender. Remove the vegetables and place them with the onions.

Add the green pepper strips and the beans. Cook uncovered 8 to 10 minutes. Add these vegetables to the other and pour the marinade over them. Refrigerate at least 4 hours or overnight.

To serve, remove vegetables from marinade and arrange on a platter. Spoon some marinade over them and garnish with lemon and parsley.

Other vegetables that may be used include mushrooms, celery hearts, leeks, cauliflower, artichoke hearts, cucumber, eggplant, and red peppers. ORIENTAL CHICKEN SALAD 3 pounds chicken piece (thighs and legs are best) 3 tablespoons imported soy sauce 1/2 cup chopped fresh ginger root 1 onion, stuck with 2 or 3 cloves 3 cups carrots, cut in thin strips 1/2 pound rice noodles (sold at Oriental food store) 6 tablespoons seasame oil 1/4 cup peanut butter 1/4 cup rice wine vinegar 1 tablespoon water 2 tablespoons lemon juice 1 tablespoon honey 1/4 to 1/2 teaspoon hot pepper sauce 2 scallions, minced

Combine chicken, 2 tablespoons soy sauce, ginger root and onion in a pot and add water to cover. Simmer covered for 30 minutes or until chicken is tender. Cool in the liquid, then remove skin and cut meat from the bones in strips.

Cook rice noodles until tender. Rinse and drain well. Toss with 4 tablespoons seasame oil in a bowl large enough to hold all the ingredients.

Drop carrots in boiling, salted water and cook for 1 minute. Transfer immediately to cold water, then-drain. Add the carrots and chicken to the noddles.

In a small bowl place peanut butter. Stir in remaining 1 tablespoon soy, 2 tablespoons seasame oil, vinegar, water, lemon juice, honey and hot pepper sauce. When it is smooth, taste and adjust seasoning as desired. Add this dressing and 2 minced scallions to the noodle mixture and toss well. CURRIED PORK AND MACARONI SALAD 3 cup cooked, diced pork 4 cups cooked macaroni 3 cups diced cucumber, peel and seeds removed 2 tablespoons white wine vinegar 2 tablespoons chives 3/4 teaspoon dry mustard 3/4 teaspoon salt 1/4 teaspoon pepper 1/4 cup olive oil 3/4 cup mayonnaise 1 teaspoon curry powder, or to taste Sliced radishes and lettuce for garnish

In a bowl combine vinegar, chives, mustard, curry powder, salt and pepper. Stir in oil. Add to pork and marinate at room temperature about 1 hour, tossing several times.

Toss cucumber with a tablespoon of salt and place in a colander to drain.

Mix mayonnaise and curry powder in a bowl.

Combine pork and macaroni. Add cucumbers and mayonnaise and mix well. Transfer to a serving dish lined with lettuce and garnish with sliced radishes.