Open 6 p.m. to 2 a.m. weekdays, to 3 a.m. weekends; kitchen open until midnight. AE, BA, CB, MC. Reservations until 9:30 p.m.

Prices: Cover charge, $3; platters $7.95 to $12.95; sandwiches $3.50.

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-ramdom 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 advertisements for the Plum read, "Dinner served." That is an exaggeration. Even with a reservation, a couple dining alone has to fight to be offered something more than a sofa and coffee table (to share) for dining. We were, after being very firm about wanting a real table to eat at, given a choice of a table on the stage next to the disc jockey or a tiny table that we would have to vacate in half an hour because it was meant for four.

That's only one reason nobody but us seems to dine at the Plum. another reason is that eating a steak at the edge of a disco floor, colored lights flashiing and chiffon skirts swirling, has a certain nightmare quality of being forced to finish your dinner before you are allowed to go out to play with the kids. You feel silly. Or maybe punished. You chew faster as the music sets your pace. The damp, chewy steak, gray on the outside as well as the inside (except when it is blue or green under the lights) bends the flimsy fork as you try to cut it. The waitress stops by to mouth in the din, "Is everything okay?" It took 30 minutes to get a drink, and you needed it by then. Your dinner choice consisted of steak, veal francais, fried shrimp, club sandwich or steak sandwich-no appetizer or dessert choices. And by the time your dinner arrived-55 minutes-you had intimately examined the table setting (two ashtrays on a badly mended blue tablecloth) and were anticipating how ridiculous you were going to feel cutting a steak to "The Freak." The waitress set down a ketchup bottle, which hinted that dinner was on its way.

The onion rings were crisp. The french fries were hot. The iceberg lettuce had a lot of diced cheese tossed with it. The club sandwich seemed more apropriated to eat in the setting. With cover charge and one chemical-flavored drink per person, it came to $32. The group at the next table shared their birthday cake with us.

The dancing deserves rave reviews.