1073 31st St. NW. 965-6666. Open Sunday through Thursday 11:30 a.m. to 11:30 p.m., until midnight Friday and Saturday. AE, M, V, Choice. First come, first served. Prices: Appetizers and salads 95 cents to $4.95, entrees $5.50 to $11.95. Full dinner with drinks or wine, tax and tip about $20 to $25 a person.

ONCE A MOTORCYCLE SHOWROOM, now a showroom for people -- that's Paper Moon. But while you are hanging out just being there, you've got to do something to pass the time, so you eat. The room, the food -- they are background. The crowd is the thing. You are where you eat.

Why Paper Moon? Because it is unique in Washington. A cavern of a space has been painted jailhouse gray with accents in mauve and near-blue and decorated post-disco with neon -- restaurant neon, not shopping-strip neon. It has stunning and stark geometric flower arrangements in tall black vases. Its artwork consists of yards of white fabric looping down from the ceiling, a new wave vision of the back yard on laundry day. The lighting is like moonlight done by a synthesizer. The tables are black marble and spotlit as if somebody were expected to dance on them. Glitzy but far short of garish, with very little in actual decoration, Paper Moon looks alive and savvy, as exciting as a spelunking expedition.

It also has better food than it needs to have, given that the tables more or less serve as a place for the audience to watch the happening-in-the-round that is the bar, a bar the size of one of the minor auditoriums at the Kennedy Center. Is the bar a waiting room for the tables? A staging area for forming a group to dine? An apprenticeship for earning a seat to watch the newcomers? In any case, dinner is the ticket for watching the show.

You wouldn't expect serious food, and indeed you don't get it. You get fun food, but not polyester stuff. The basil in the tomato salad is fresh; the olive oil is the expensive green kind, and a whole bottle of it is brought to the table with balsamic vinegar for you to dress your salad.

There isn't a lot of variety on the menu: 10 appetizers, pizzas, frittatas, about a dozen hot pastas, a few grilled dishes, and salads of pasta, seafood and chicken. Mostly it is a pizza- and-pasta place (albeit very modish pizzas and pastas). I would narrow that even further: I'd skip the pizza and just have appetizers and pasta.

I'd start with panzaroti, a fried dough oozing with four cheeses. The dough is thin, crusty and chewy, a fine hors d'oeuvre with drinks. As for the drinks, this bar makes them with fresh ingredients. The wine list is quite small and indifferent but some are very reasonably priced (Domaine Chandon Blanc de Noirs is $19, Dom P,erignon $65, if you are in a champagne mood; the $17 barolo is a fine wine and good value). Some of the antipasti are also awfully good; the tomato-mozzarella salad is made with very fresh cheese, and the antipasta di verdura is refreshing, fashioned from lightly cooked cold vegetables in a sweet and tangy tomato marinade. Fried appetizers -- zucchini, mushrooms, or squid -- are lightly and crisply battered, though my squid was overcooked and chewy. Mussels with butter and garlic, like most dishes, were an enormous portion but had been taken out of the shell -- too long ago. Cold squid salad was better, though not special. The menu also lists fried mozzarella, prosciutto and melon, a soup and breads topped with gorgonzola and cream sauce (not nearly as good as the panzaroti).

The pizzas sound terrific: seafood, fresh vegetable, four- cheeses, sun-dried tomatoes, wild and domestic mushrooms, lobster and the like. But they taste like upgraded frozen pizza. Their crust is crunchy and tough, their tomato topping is not distinctive, and the special toppings have their problems. Wild mushrooms, for example, were chewy and flavorless; sausage had even less flavor. As long as we are speaking of flaws, the frittatas, also, would bring a blush of shame to an Italian omelet maker; mine was greasy and chewy.

The pastas are another matter. They look bountiful served in big white porcelain bowls. You can have them sauced with exotic combinations such as snails and garlic tomato sauce, with shrimp and radicchio in cream sauce, or stuffed with a scallop souffl,e. A special of green noodles with smoked salmon in red pimiento cream was a surprisingly successful mating, and the sauce was deliciously mellow, though the salmon was so thoroughly cooked that it tasted very salty. Linguine with seafood in tomato lobster sauce also showed a flair with sauce-making. And the seafood itself was tender, juicy and fresh tasting. Only the fettuccine with four cheeses tasted indifferent, the noodles pleasantly wiry and al dente, but the sauce lacking flavor and not sufficient to moisten the noodles. As for the cold pasta salads, you are far better off ordering something hot. The tortellini with seafood would have been a good seafood salad with fresh basil and lemon without the drab tortellini in it. It was also excessively oily.

After watching people at another table complain about their grilled steaks on two different occasions, I ordered grilled tuna with trepidation. It was surprisingly good, not only the quality of the fish and the cooking -- it was cooked through to firmness but was not dry -- but the herbs and lemon highlighted the best of the fish.

Dessert you can skip altogether unless you can't resist finding out for yourself that the Italians don't understand pecan pie. There is gelato, and that they do understand. As for the espresso, they've got the taste right but not the body.

Along with this fun food is fun service -- waiters and waitresses in funky spangled pink vests, enjoying being part of this show and welcoming you into it.

If the food is not particularly serious, neither is it particularly expensive. The appetizers are all under $5, the pastas under $10 and even the steak is only $12. You could order a pizza or salad for less than $7 even at dinner. Not bad for admission to this season's hit show.