Jay Jackson -- this man could sell a plate of fried fleas. But he now manages and waits tables at the Delmar Restaurant & Lounge in the U. City Loop and instead handles carefully designed plates of culinary accomplishment. Jackson, a waiter and bartender for most of his life, has worked everywhere from underground rock & roll clubs in Los Angeles to jazz bars in New York City. He knows his liquor, his spices, his table settings and his red wines. He's been a bouncer, a soldier and an entrepreneur, so his litany of jokes, insults and one-liners is well dressed in wit. When customers walk through the door, he sizes up their personalities with the finesse of a psychoanalyst and launches into a menu of suggestions to suit their temperaments. "The meal should be an experience," he insists. He also knows his jazz and has partied with the best. Formerly head bartender at Just Jazz in the Hotel Majestic, Jackson can explain to customers at the Delmar what's happening onstage with the patience of a primary-school teacher or converse fluently with aficionados. The Delmar is open 5 p.m.-3 a.m, with live music Wednesday-Sunday. On those nights, ask for Jay.