It's not too early to think about booking a table at one (or more) of the estimated 100 area restaurants that plan to participate in Restaurant Week (Jan. 10-16), the biannual industry promotion begun in November 2001 as a way to help fill Washington dining rooms following the 9/11 terrorist attacks. The deal, for those who haven't sampled it before: three-course menus offered for $20.05 at lunch and $30.05 for dinner. "It's win, win, win for all concerned," says Lynne Breaux, executive director of the Restaurant Association Metropolitan Washington. The campaign, timed when business is typically slow for chefs and servers, is a "fabulous introduction of the restaurant to new, sometimes younger, clientele," she says. It's not bad for the restaurants, either: They report increases of 15 to 200 percent during the promotions. A complete list of participating restaurants can be found at www.ramw.org.