GADSBY'S TAVERN in Old Town Alexandria is an elegant and authentic taste of colonial America. Although it's nice to use visitors as an excuse, you can drop by George Washington's old watering hole any time for venison, prime rib, Sally Lunn bread and pecan pie. After sundown you're serenaded by 18th-century minstrels.

Inside the restored 1792 hotel, it's Williamsburg without the three-hour drive. Chippendale chairs, dark bare wood tables, antique carved buffets and pewter place settings all gleam in the candlelight. The waiters are clad in breeches and buckled slippers, with lace jabots at their throats; the serving wenches wear full-hipped long skirts, laced bodices and bonnets.

But Gadsby's has something Williamsburg hasn't got -- Kathleen Baker, who on Sunday and Monday evenings presides over "Publick Table." Two dozen utter strangers sit down at a U-shaped table and let Mistress Baker -- in petticoats, stays and bonnet -- whisk them into the 18th century.

From the moment the serving boy announces your arrival, Baker takes charge. Hailing you heartily by name from across the candlelit room, she bustles you to the nearest empty seats. After everyone's been introduced, Baker sets the scene in her arresting 18th-century diction: "Good evening kindest ladies and gentlemen. It is indeed a privilege and an honor to serve you at Mr. Gadsby's Tavern on this balmy autumn night in 1784." And off you go.

Baker, always deferential to the "people of quality" but saucy as an unmarried wench should be, takes your drink order and works the table, sharing bits of 18th-century Alexandria gossip and jokes. She may offer to rustle up mates for the unmarried guests from among the diners or attempt to sell her own indenture papers to some likely man. "I'm a wench open to possibilities," she says coyly.

By now you're getting used to being in the olden days, and as dinner gets under way your attention turns to the table, set with a linen cloth and bearing pewter bowls filled with pickled miniature corn and garden vegetables and huge baskets of warm, dense Sally Lunn bread with accompanying pots of butter. True to the period, the salt is set out in bowls, and the sugar is a tall crystal cone -- you scrape off what you need.

Dinner's served family-style by Baker, with the help of a lad or two. This night, the feast commences with seafood pasties (pastry- encased shrimps and crab). The main course is a magnificent 25-pound roast of beef that's first presented for approval, plus platters heaped with roast chicken. Steaming kettles of baked beans and huge bowls of squash go round. Baker carves, keeping a close eye on guests' plates and urging second and third helpings. Dessert is trifle, but hardly trifling -- it takes two young men to lug the deep glass bowl filled with sherry-soaked pound cake, custard and whipped cream.

And then the real fun begins. Glasses are filled with sherry, port or madeira and the toasts commence. The first is a noble toast to General Washington, sung by Baker in a ringing soprano (in her 20th-century incarnation, she's a founding member of Philomela, the chamber music singers). It's all downhill -- in terms of decorum -- from there. Baker persuades one young woman to recite the "Ladies' Toast to the Men": "We women may have many faults / But men have only two / Everything they say / And everything they do." Loud cheers of "Huzzah!" go up whenever a toast is well received.

After everyone's toasted or been toasted -- and some people really get into the spirits of the thing -- Baker takes up her dulcimer and performs from her wide repertoire of period chamber music, folk ballads from Europe and Appalachia, war songs and drinking ditties, one of which advises: " 'Tis safer for ladies to drink / Than to Love." But the hit of this evening is a gently ribald song about a ''Scotsman's Blue Ribbon," sung especially for visitors from Canada, Master MacGillivray and his good lady, whom Baker has been teasing for being Loyalists rather than Patriots.

After the singing and carousing, it's hard to wrench yourself from the colonial spell, but you simply have to get up after 21/2 hours or so at table. Emerging into the cool night air, you can hold on to that 18th-century feeling -- and walk off some of your dinner -- with a stroll along cobblestoned Captain's Row, just a few blocks southeast on Prince Street. GADSBY'S TAVERN -- 134 North Royal Street, Alexandria. Publick Table is held Sunday and Monday evenings at 6:30. Dinner is $16 per person, and includes appetizers, main course, dessert, coffee or tea and an after-dinner glass of sherry, port or madeira. Mixed drinks are about $3.50, and beer $1.50 to $2.50. Publick Table reservations: 548-1288.

From 9 to 11 on Sunday and Monday evenings, Baker is also the hostess of the drop-in Gadsby's Gambols, with 18th-century music, games, singalongs and colonial characters mingling with guests who are offered "libations and light fare."