The best bazaars are the ones you can smell blocks away.With its sharp, lemony smells of lamb and marinating olives wafting out from the tents, the bazaar of Saint Sophia Cathedral is one of the city's favorite epicurean traditions.

Here, for instance, you could run a gauntlet of trays to discover the soft, heavy texture of the royal olives, the color of malted milk balls: the bite of the brine-soaked cracked dried Cretan fruit and the huge Calamatas from Peloponnesus.

Here too were the cheese with neames like music: kefalotiri, kasseri, feta and fontenella. And the jars of taramosalata - caviar whipped with olive oil - and grape leaves, and the pint boxes of hot green peppers. And bottles of licorice-flavored ouzo and Greek wines and imported beers.

Great piles of chicken origanato, moussaka, menestra and shiskebob vanish during the three-day event at 36th Street and Massachusetts Avenue NW., but it was the pastries that were the real stars of a Greek bazaar. Baklava, kadaifi, Koulouraka and others with as big a mouthful of syllables as the deserts themselves were prepared by the hundreds by the congregation members. It was not unusual to find a stuffed visitor, eyes glazed, surrounded by the empty papers of a half-dozen assorted pastries.

Like many bazaars, the Saint Sophia event is a fund-raiser for the church, which intends to build a youth/education center on a nearby property. It and several other bazaars were held on a recent weekend.

The Christmas bazaar of the Hungarian Cardinal Mendszenty Society benefits that organization's social programs for Boy Scouts, Hungarian community senior citizens and others.

Brilliant and crowded inside a placid stone building on the grounds of the Franciscan monastery in Northeast, the Hungarian bazaar included a crowded exhibit of handiwork and art from private collections.

Arpad Sayko, a solid, humorous man who has lived here since 1937, waved his hand toward a manikin wearing a dress so heavy with embroidered flowers that the black material underneath is almost obscured.

"In Hungary, there's no hanging around the drugstore," he joked. "The grandmother is the babysitter, and she starts by teaching the little ones how to thread a needle . . . telling stories and sewing . . . then they're 50 or 60 years old and can do that."

According to Sayko, the present Hungarian government "goes out of its way to encourage art," often buying works for its collections.

The red and black wall hangings are not printed, as they appear, but are laboriously cut out of felt and glued together in the same way schoolchildren scissor out snowflakes and valentines.

The food, as always, was a strong selling point - the gloulash chicken paprika and stuffed cabbage - but the main attractions on the sale tables were the delicate Christmas tree ornaments made of blown-out eggshells lacquered and hand-painted, or the more expensive porcelain ornaments made in limitation of the eggs.

There are, of course, bazaars at which the food is limited to sandwiches and cupcakes, where the main attractions are the jewelry and toys and art and books. The annual Christmas bazaar at Stone Ridge school, just north of the District line in Bethesda, was spread out over three separate buildings of the campus, and the entire gymnasium was given over to the 70,000 volumnes of the book sale.

According to Mrs. James Corcoran, mother of four Stone Ridge students, the book sale annually nets $10,000 to $11,000 for the school. In 1977, the whole event netted $54,000, making it one of the most successful bazaars in the area.

Stone Ridge divided its bazaar into two events a fortnight apart. First was the auction dinner, at which the highest bidder could walk off with lunches with Ted Kennedy, Fritz Mondale, Tip O'Neill or Joe Califano; a living room suite or a mention in "Ear"; a week for two in Acapulco or two nights at the Madison Hotel; four tickets in the owner's box of the New York Yankees, or tickets to the Caps, Bullets or 'Skins games.

The bazaar also included about 400 pieces of art from 62 local artists, hung in the parlors of the school's main building. "Grandmother's Treasures" in the stable ranged from cut glass to typewriters, and in the booths left-handed accessories vied with factory-special skateboards (regularly $50, now $20).

According to Joan Gillespie, the school's director of development and chairman of the bazaar, much of the money raised is used to provide scholarships to maintain the "deliberate . . . divergence" of ethnic and social backgrounds among the students.

A bazaar like the Christmas Corner at Alexandria's Christ Church may benefit the community as a whole. The Junior Friends of the Alexandria Y (no longer associated with the national YWCA; its members says the Y stands for You) coordinate displays and exhibits from as far as away as Texas to raise money for their projects benefiting senior citizens, prison inmates and halfway houses.

Here the traditional ran headlong into the fashionable, with tiny wooden soldier ornaments competing with $250 deluxe Cuisinarts. In the hallway, Fred Laughon constructed his miniature bureaus and four-posters, while a group of well-dressed women sorted through name-label sportswear.

Bazaars will be cropping up all over the metropolitan area from now until Christmas. Watch for those corner-lot, freshly painted signs. Where else can you eat, buy a gift and support a good cause all in one afternoon?