Open daily, 11 a.m. to 11 p.m. Reservations suggested. AE, CB, DC, MC, V. Prices: Weekday lunch specials $4.75. At dinner appetizers $7.50 to $20, main dishes average $7 to $8, desserts $1 to $2.

A second-floor dining room of a Crystal City high-rise apartment is the last place we expected to yearn for a guidebook and dictionary. But that's not the only surprise at this elaborate Korean restaurant.

I feel at a disadvantage writing about this restaurant, since even after sampling most of the menu I can't decipher much of the food or instruct you on how it is to be eaten. And that's its problem. This restaurant, which has branches in New York, Los Angeles and several Asian capitals, offers a menu broader than any Korean restaurant I have seen. But you are pretty much left to flounder through it on your own, since the waitresses--charming, industrious and gracious though they are--speak too little English to help you. If you order anything from the bar as complicated as Campari and soda, you'll have to write it out. If you want to know something more specific than the "fish, shrimps, beef and chicken" or the "nine kinds of Korean hors d'oeuvre" specified on the menu for the $20 appetizers, you wind up playing Twenty Questions, with the waitress pantomiming the cooking method --and later discover that on a busy day they may need to be ordered ahead anyway. "That's cinnamon," said a waitress, proudly displaying a persimmon. And the ma.itre d' h.otel communicates no better.

Enthusiasm counts for a lot here, and is infectious if you don't mind risking a few dishes that you may neither understand nor like.

A few rules will help: Along with the familiar oriental seasonings--soy sauce, garlic, ginger, scallions, sesame oil and seeds--the taste that pervades Korean food is a hot red chili paste that has a flavor as distinctive and earthy as coriander leaves and a heat that sneaks up on you. Thus you should approach with caution any dish that is tinged with red until you have assessed its fire.

If you are going to be four or more at dinner, order ahead for one of the two $20 appetizer platters; besides being beautifully decorated with carved vegetables, they offer a sampler of Woo Lae Oak's best. Modum Yori was a large display of grilled salmon, fried chicken bits, cold spiced tongue and pork, sweet-salty aspics, marinated jellyfish, fish fried in an egg batter, candied chestnuts and a delicate rolled omelet studded with bits of vegetable.

The other appetizers--costing $8 to $9--are also meant to be shared, as they are more costly than the main dishes. If you like Japanese sashimi, you should try the Korean version, raw white fish fillets (no tuna) cut thicker than Japanese, and dipped in vinegary red pepper paste as well as soy-wasabi. There is also an appetizer of shredded raw beef marinated with sweetened soy and sesame seeds to dip in raw egg and pepper sauce, and there are a couple of deep-fried cousins to tempura, shrimp and spiced spongy meatballs.

Familiarity begins to disappear with the main dishes. The most conservative choices are grills. The waitress uncovers a gas jet in the center of the table and sets a grid on top of the flame for cooking bul goki (thin-sliced beef marinated in soy, garlic and sesame), short ribs, chicken, beef innards--or pork seasoned with that red pepper paste. These are the mainstays, the reason for the overhead wood-trimmed exhaust fans and the source of the wonderful smells and smoky haze issuing from the banquet rooms. Hot pots--in the mode of Japanese sukiyaki and yosenabe--are also cooked at the table. But if you don't want to be your own chef--or sous chef--you can get meats and fish saut,eed in egg batter as tiny omelets (the meatballs are particularly savory). You can find various noodles or dumplings in broth with meat and vegetable garnishes. The mandu-dumplings, like fat won tons, float in broth alone or with chewy rice cakes, and serve as a filling and aromatic main course. There are m,elanges of translucent noodles with slivers of beef, tree ears, scallions and other vegetables, all seasoned with soy and sesame oil (chop chae); and fat chewy rice brought to the table in a huge bowl topped with beef, vegetables and fried eggs, to toss together with as much red pepper paste as you require (bibim bap). And there are rice porridges akin to the Chinese congee (jook). Or you can beg the question and try "assorted Korean plate dinner," which comes with a thick-as-stew miso and bean curd soup, a meat brochette, egg- battered fish and a bewilderment of side dishes including three different kinds of kimchee, those explosive fermented peppered vegetables that separate the dabblers from the brave Korean aficionados.

Whatever you decide, your table will fill with side dishes: cold sesame-oiled spinach and bean sprouts, vinegared radish, kimchee, soy and pepper dips, covered metal bowls of rice, cubes of mysterious jellies, squares of black seaweed, tiny dried fishes. Which goes with what? Are they to be combined or eaten in succession? The waitress shrugs, smiles and says, "Whatever you like."

It is a dinner to pick at and nibble, to adore this and reject that. Whether it is good cooking depends as much on your facility for balancing your mix-and-match components as on the kitchen's work.

You needn't save room for dessert, which is either ice cream, fruit or a dense, hard, greasy and incredibly sweet fried pastry square called yak gua. There are also two kinds of sweetened water, one seasoned with ginger and afloat with a dried persimmon, the other littered with tiny white bits of fermented rice. But they both taste like just bowls of sugar water, hardly the American idea of dessert.

Woo Lae Oak issa large simply decorated dining room, enhanced and given character by touches of wood, from the trim of the overhead exhaust fans to the thin slats on the sliding window screens. The canned music disrupts the oriental mood, but otherwise the exotic East prevails.

A small adventure, with modest financial risk and a chance to taste the unfamiliar--that's the spirit at Woo Lae Oak.