Thanksgiving, unlike Christmas and Easter, is the only feasting holiday in America which is non-denominational. This probably accounts for its unflagging popularity as a time for family gathering even as other family-centered activities seem to be on the wane.

Many people feel so strongly about it that if they have no families wth whom to celebrate they seek out a substitute-family for the occasion. One good friend, who has all the instincts of a mother-hen anyway, has a houseful of Thanksgiving diners each year who are strangers to each other. They have one thing in common besides their good fortune to know the "mother-hen" - no place to go for the holiday.

Because Thanksgiving is a native celebration, the foods served from North to South and East to West pbear some similarity to each other. People have not incorporated traditions from other lands into their meals and while everyone does not serve turkey, they usually serve some kind of bird. To do otherwise may incite family riots.

After years of hearing her children complain about turkey at Thanksgiving, one woman decide to suprise and hopefully please, them by serving something they did like - pot roast. The cries of dismay that greeted the arrival of the non-traditional, non-fesitve pot roast taught her a lesson. She never served anything but turkey again.

Today's Thanksgiving dinner is, however, a somewhat streamlined version of those served at the turn of the century, at least in the homes of the rich. When Theodore Roosevelt and his brook observed Thanksgiving at Sagamore Hill, they feasted on: oysters on the half shell, celery, radishes and olives followed by consomme. They came the roast turkey with chestnut stuffing and giblet gravy plus rpast suckling pig. (Roosevelt and his famous daughter Alice are reported to have been extremely fond of suckling pig.) To accompany them: cranberry sauce, spiced crab apples, spinach, mashedpm: cranberry sauce, spiced crab apples, spinach, meshed potates, onions in cream, Brussel sprouts and salad. To finish off the meal (and the guests) mincemeat pie, pumpkin pie, vanilla ice cream, nuts, fruits, chocolate dragees and coffee.

Most late 20th-century Americans would have a lot of trouble consuming that kind of meal. But in keeping with the tradition, for this year's feast the Food Section offers its family favorites.

To start the meal, oysters and champagne. For the main course, what else but turkey with a Victorian stuffing plus an abundance of side dishes and for dessert, pumpkin pie, with a twist. VICTORIAN STUFFING

(Enough for 10 to 13 pound turkey) 1 pound loaf unsliced white bread 1/2 of one pound loaf egg bread, unsliced 3/4 cup rye bread, torn in bits 1/4 pound butter 3 onions, finely chopped 1/3 large bunch of celery, chopped 3 ounces fresh mushrooms, sliced 1/3 of 12 ounce can chestnuts, drained ad broken in small pieces. 1/2 pound fresh sausage Turkey liver, diced Salt and pepper to taste Sage and thyme to taste 2 eggs 3 1/2 to 4 cups chicken broth

Cube white and egg bread into 1/2 inch cubes. Add rye. Place in large roasting pan and toast at 275 degrees until cubes are as dry as Melba toast; turn often. Melt butter, add onions, celery, including leaves. Cover and cook until onions are slightly golden. Add mushrooms and cook, covered, for 10 to 15 minutes. Add onion mixture to bread with chestnuts. Fry sausage until brown; drain off fat, reserving a little of the fat in which to cook the turkey liver. Cook turkey liver. Add sausage to stuffing mixture. Add turkey liver. Season with salt, pepper, sage and thyme. Beat eggs well; add. Carefully stir in chicken broth. Adjust seasonings and stuff turkey cavity and neck. DOROTHY'S CARROT CAKE

This is not served as a dessert, but as an accompaniment to the turkey.

(8 servings) 1 cup shortening 1 cup dark brown sugar 1 teaspoon salt 1 tablespoon cold water 1 tablespoon lemon juice 1 tablespoon vanilla 2 eggs, separated 1 cup cooked mashed carrots 1 1/4 cups flour 1/2 teaspoon baking powder 1/2 teaspoon baking soda In large bowl thoroughly mix the shortening, sugar, salt, water, lemon juice, vanilla, beatne egg yolks, carrots, flour, baking powder and soda. Beat egg whites until stiff but not dry. Fold into batter. Spoon into greased 2-quart ring mold and bake at 350 degrees for one hour. Unmold to serve. Center may be filled with vegetables.

In order to have as little last-minute work as possible, most of the ingredients can be combined in advance. Omit the baking powder, soda and egg whites. Refrigerate the batter. To serve, allow batter to sit at room temperature 30 minutes. Stir in baking powder and soda and continue with directions. PUMPKIN APPLE PIE (8 servings) 1 cup cooked or canned pumpkin puree 1 cup applesauce 1/2 cup light brown sugar 3/4 teaspoon salt 1 1/2 teaspoons cinnamon 1 teaspoon nutmeg 1/2 teaspoon cloves 1/4 teaspoon ginger 4 eggs, well beaten 1/2 cup heavy cream 1/4 cup milk 9-inch unbaked pie shell

Combine the pumpkin, applesauce, sugar, salt, cinnamon, nutmeg, cloves and ginger. Blend in the eggs. Scald the cream and milk and then add slowly to pumpkin mixture. Mix throughly and pour into pie shell. Bake at 425 degrees for 45 to 50 minutes or until knife inserted in center comes out clean. Cool and chill. Garnish with whipped cream, if desired. CRANBERRY SALAD MOLD

(8 to 10 servings) 2 packages unflavored gelatin 3 cups orange juice 2 cups ground raw cranberries 2 oranges, seeded and ground 2 cups finely chopped celery 1 cup chopped walnuts 1/2 cup sugar Soften gelatin in 1/2 cup orange juice and dissolve over low heat. Remove from heat and stir in remaining juice. Chill until partially set. Combine cranberries, oranges, celery and walnuts and stir in sugar. When gelatin mixture is partially set, add cranberry mixture and pour into 8-cup mold. Chill until firm. Unmold to serve. HOT HERBED TOMATOES

(6 servings) 1 1/2 pints cherry tomatoes 6 tablespoons finely minced inion 1 large clove garlic, finely minced 6 tablespoons chopped parsley 1/3 teaspoon dried thyme 3/4 cup soft bread crumbs Dash pepper 6 tablespoons olive or salad oil

Stem tomatoes and wash; drain. Combine remaining ingredients; mix well. Arrange tomatoes in single layer in lightly oiled, shallow baking dish. Sprinkle bread crumb mixture over tomatoes. Refrigerate, if desired. To serve, return to room temperature and bake at 425 degrees for 6 to 8 minutes, or until tomatoes are softened.