Open daily, 6 p.m. to 2 a.m. All major credit cards. Reservations weekdays and for 7 and 10 p.m. seatings weekends.Prices: appetizers and snacks, average $3 to $5; main dishes $6.50 to $17.50. Specialty drinks, $2.50 to $3.75.

Dining and dancing is one of those wonderful ideas that somehow usually works to the disadvantage of one or the other activity. The choice seems to be between dining and dancing or dining and dancing . When dining is the central focus, the dancing may be off in another room or only at odd hours (sometimes only after the kitchen is closed). When dancing is the main theme, dining may be a backhand attempt at bringing in easy revenue at whatever cost to your digestive system.

In a not-quite-random sample of dining and dancing opportunities in the Washington area one emphasized the dining, one emphasized the dancing, and the third one found a balance that was just right. So I'll start with the third, the dessert of this sampler.

The most even-handed combination I found was at F. Scott's. But that is no secret; everybody waiting in line to get in on Saturday night can tell you that F. Scott's is a good place to dine, dance, drink, meander. It is the city's best grown-up ice cream parlor, only here the ice cream is alcohol-laced and served with a straw.

It is hard to resist feeling like Fred Astaire and Ginger Rogers at F. Scott's. The tape plays "Moonglow." and you foxtrot on the small dance floor, its ceiling reflecting your agile dips and glides. "In the Mood" turns your jitterbug into an MGM routine, your swirls caught in the Art Deco lucite and mirrored planters. You dance to the Big Bands, and even though the Life magazine covers and sheet music on the walls are relics, you join them in being young and glad to be alive in 1949.

Everybody has his own version of romance; at F. Scott's it is tiny tables, close together, a champagne party atmosphere where black tie would not be out of place. It takes only moments to feel like a movie extra. A young Diane Keeton smiles her way to your table, sweetly takes your order and always remembers your soup spoon and wine refill. You sip pretty pink things in stemmed glasses, a perfumed frozen slush called Ice Palace, or an antique-satin cream called Toasted Almond. Small drinks they are, but they taste as if they were designed by Busby Berkeley.

In such a setting one is tempted to order Cream Chicken Stork Club ($5.75). Resist. It is mostly toast, and has factory undertones. The supper menu also includes eggs and roast beef sandwich and a pretty good tartar steak ($5.75). This is a menu aimed at late night snacking, with twice as many appetizers as main dishes. For light eating, order the oysters and clams by the piece (50 cents, a better buy than the $3.95 raw bar platter) or a platter of three decent-to-good pates ($4.50).

Life in the movies is full of happy surprises, and F. Scott's version is the pasta section of the menu. The fettucine, agnolotti and tortellini are homemade by a talented behind-the-scenes bit player, cooked al dente, and tossed in rich creamy sauces. Along with the drinks, they are the stars of the show.

On occasion the veal-and-steak-oriented main courses include beef wellington, a fine conjunction of rare filet of beef, chopped fresh mushrooms and crisp puff pastry, the best buy on the menu at $8.25, but be sure to ask for the sometimes-acrid sauce on the side. Dessert is billed as an extravaganza of pastries, souffles, banana splits and the like; the choice in reality is smaller, but the strawberries are generously drenched in curacao and whipped cream for a sweet alcoholic finale.

No wonder it is a hit show. The food, if not worthy of awards, plays a good supporting role to a glamorous stage set.