Smorgasbords and buffets have much to recommend them, but it is the Arab world that has perfected the "a little of this and a little of that" mode of dining.

The Arabic version is called mezze, and it can be as extensive as any buffet table. It has one distinct advantage over its European counterparts: you sit at the table and it comes to you. While mezze starts out to be an appetizer, it often becomes the whole meal. It can be lunch or dinner or last from lunch to dinner. In Washington a mezze could be fashioned from any Middle Eastern restaurant's appetizer list, but those restaurants that recognize it as an art and produce a full range of dishes to cover your table at the mere sound of the word are the Lebanese restaurants. Here is how three of them do it. FETTOOSH 3277 M St. NW. 342-1199.

Open from 11 a.m. to 1 a.m. Sunday through Thursday, until 2 a.m. Friday and Saturday. AE, CB, DC, MC, V. Reservations suggested. Prices: Individual mezze dishes are $1.50 for meat, $1.25 for vegetable; 15 dishes are $17.50 for vegetarian, $20 for meat and vegetable; 25 items are $32.

Fettoosh is a forest of decorative tiles and shellacked tree trunks. Entering, you pass the open kitchen, piled with carrots and grapefruits ready for the juicer, into the din ing room, its booths formally set with white cloths and flowers. Waiters are eager to guide you through the labyrinthine menu, which lists among other things nearly 40 mezze possibilities.

While you decide, a small dish of roasted seeds and another of pickles and olives appease you. The dining process goes easiest, of course, if you leave the assortment to the kitchen; you'll get a range of salads, meats, stuffed doughs and vegetables that could serve as dinner, for $7 or $8 a person. The waiter will also suggest arak, the licorice-flavored liquor that is the standard accompaniment; for non-drinkers there are juices of carrot, apple or orange. Given the blandness of Fettoosh's appetizers, we would settle for beer.

I wish someone could fire up the kitchen to take a stronger stand in its seasonings. The homemade sausage, soujouk, was only faintly spicy, the raw kibbe -- finely minced lamb -- had no discernible seasoning, and the various meat, cheese and vegetable pies, pretty little pockets and turnovers though they were, tasted sadly bland. The best of our 25 appetizers, all on oval white dishes that nearly covered the table, were the thick yogurt spread, lebne, the golden fried cauliflower dipped in lemony sesame paste and the salads of beans and potatoes. Otherwise the vegetables--primarily green bean salads and chopped raw vegetables--were watery, the stuffed and fried vegetables lacked character and the saut,eed meats were tough and dry. You can hardly go wrong throughout the Middle East with hummus and baba ghanouj, and those two sesame-paste spreads were just fine at Fettoosh. The meal was most notable, though, for pleasant service and for two desserts, a melted white cheese with a semolina crust and nut-studded syrup, and supersweet crepes, appealingly filled with nuts and soft cheese. BACCHUS 1827 Jefferson Place NW. 785-0734.

Open for lunch Monday through Friday noon to 2 p.m., for dinner Monday through Thursday 6 p.m. to 10 p.m., Friday, Saturday 6 p.m. to 10:30 p.m. Closed Sunday. AE, MC, V. Reservations suggested. Prices: Individual appetizers $2.50 to $6.50.

With a little initiative you can concoct the best mezze

in town at Bacchus. The prices may seem high if you

have been used to the 15-dishes-for-$20-to-$30

deals, but at Bacchus the portions are large. Two

appetizers make an adequate meal for one.

Don't miss the hummus special, the familiar sesame-chick- pea dip in this case served hot topped with chopped meat, pine nuts and almonds. Like all the appetizers at Bacchus, it is attractively decorated; some dishes have stripes of powdered dried herbs, others are patterned with minced parsley and most are garnished with sliced tomatoes or lemons.

Beyond the hummus special, you should try one of the two homemade sausages, particularly the searing and tangy soujok, as hot as any Mexican chile-head could desire. And there is a cheese-filled pastry, a long cigar of homemade phyllo dough oozing with several cheeses that pull into long strings as you bite in, and aromatic with black sesame seeds. There is also a meat-filled version of this fine pastry. The fried cauliflower here is served hot, crisp both from the frying and from its near-rawness, with a light and fluffy lemon-sesame dip. Among the hot appetizers, only kibbe, dry and flavorless, has been a disappointment, though it was beautifully shaped. Among cold appetizers, tiny eggplants stuffed with pomegranate-and-onion-flavored rice were intriguing. The cured beef, basterma, was fiery from its spice coating. Also there were versions of hummus with and without fava beans, the usual tabulleh, grape leaves and chopped vegetable salads, and raw kibbe that is lightly seasoned and well made. AL KHAYYAM 2605 24th St. NW. 265-7233.

Open 11:30 a.m. to 1 a.m. Sunday through Thursday; 11:30 a.m. to 2 a.m. Friday, Saturday. MC, V. Reservations suggested on weekends. Prices: Mezze of 16 dishes is $30.

The crowd drifts in late at Al Khayyam, for the focus here

is not the kitchen but the dance floor and its belly danc er. It must be a good show, good enough for the return ees not to notice that the food is pretty depressing and

the service absent-minded. The baba ghanouj and hummus are good enough, but the kibbe in its raw and cooked form lacked all zest. You could do all right with the Arabic salad -- chopped raw vegetables in a lemony dressing -- and fragrant, tangy stewed chick-peas; liver was likewise in zesty pan juices though of indifferent quality. The felafel had a pleasantly light texture but little taste, a characteristic also of the tabulleh, cold fried potatoes, grape leaves. In addition, though, the 16 dishes included one of carrot sticks, another of hot peppers, a third of olives, hardly a lot of exotic fare for the money. And as uninteresting as it was, it beat by a mile the dried out, chewy main courses. Should you find yourself under the arches and nightclub lights of Al Khayyam, however, you can find a likable Greek ros,e wine to accompany your mezze and very good Turkish coffee to end the meal.