Prices are lower by $1.00 per entree at lunctime. No reservations. BankAmericard, Master Charge, and American Express Cards are accepted. Phone 836-5676.

There are two qualities that, in my book, make a restaurant pleasant for eating out "en femille," especially when the famille includes two pre-schoolers. The folks who brought us McDonaldland and Happy Trails learned the tricks long ago - quick service and decorative gimmicks. Nothing will keep a child out of your hair better than a plate of food quickly brought. And when that's done with, it helps if there's something novel to look at.

The Fish Market, 105 King St., Alexandria, offers both quick service and an interesting decor and while they don't exactly encourage the stroller trade (there are no boosters seats or high chairs, for instance,) it is a very good place to take children.

Housed in a refurbished warehouse near the river, the Fish Market looks like what it's called. But beyond the fish counter and through the swinging doors there is a restaurant-bar. Big circular fans hang from the ceiling. There's plenty of pine paneling and nautical knick-knacks are hung about. On the brick walls are painted large murals depicting what life in an Alexandria fish market might have been like circa 1800.

Restaurants in Old Town Alexandria tend to start filling up around 7 p.m. on a Saturday, so we arrived a little earlier on a recent week-end. The Fish Market is a very informal place. No reservations are taken, and you can sit at any table you choose. All of them are covered with red checked cloths and none of the little wooden chairs quite match each other.

We found a table beneath a large blackboard on which the day's menu was chalked up. Several of these boards are hung around the room at strategic locations. There are no printed menus at the Fish Market.

Our waitress appeared, took a look at the children and thoughtfully dashed back into the kitchen for a bowl of oysterette crackers, which kept them busy until their "flippers" arrived. "The "flipper" is a 50-cent kiddies' cocktail made of the old standbys, ginger-ale and and grenadine, accompanied by a maraschino cherry and orange slice on a plastic saber toothpick.

For the adults, there's the usual assortment of cocktails, plus draught beer, which comes in huge thick glass goblets. The "small" 12-ounce size is 65 cents. The large (32-ounce) size is $1.25.

We chose as a first course the $2.25 shrimp cocktail, which my husband shared with the boys, and a $1.05 bowl of creamy clam chowder, which was sufficiently peppery that I had it all to myself. For hors d'oeuvres the Fish Market also serves clams and oysters on the half shell at $1.95 and clams casino at $2.65.

The main courses are pretty standard but nicely prepared. We ate the fried oysters and scallops, at $4.25 each, and had the stuffed flounder at $4.95. All were tender, tasty, and not over-breaded. Also on the menu was shrimp creole at $3.95 and broiled rockfish at $4.95. The fried shrimp were $4.25. All the entrees come with thick oblong pieces of sauteed potatoes, a very good cole slaw, and the best hush puppies I've had north of Nags Head.

The Fish Market serves no children's portions but our waitress suggested we order three entrees and have an extra plate for the two-year-old. We all shared our scallops, oysters and fish with him but selfishy kept him in the dark about the hush puppies.

By the time we had finished our meal, the gimmicks had worn off and the children had begun to squirm. When the little one escaped from his chair the second time, we asked for our bill, which came to $19.85 without tip but including flippers, and beer, and beat a hasty retreat.

The Fish Market serves coffee, but no desserts.