It's a gastronimic happening of the scrumptious sort at Taste of the Town, Washington's annual dining and entertainment extravaganza. The menu at this year's feast includes such international and American favorites as fettucine alfredo; Irish smoked salmon; mini croissants stuffed with veggies, cheese, meat or fruit; swordfish salad; and New Orleans barbecued shrimp. And while you're pigging out, there'll be continuous music and dance numbers throughout the two-day food fantasy. Some of the performers are: Christian the Magician, Gross National Product and the Trinidad & Tobago Steel Band. Advance tasting books and admission tickets are both $5 and available at Ticketplace, Hecht's, the Capital Centre outlet at 1801 K Street NW, Crystal City Underground and the Convention Center's H Street entrance. Admission at the door on Saturday is $6 for adults, $4 for those 62 and over, $3 for kids 10 to 18; under 10s get in free. The tastings, representing more than a hundred restaurants, range from 50 cents to $1.75 per sample. The feast runs Saturday from 11 to 8 and Sunday from 11 to 6 at the Convention Center's exhibit hall B. If you're taking Metrorail, exit the Red, Blue or Orange lines at Metro Center on Eleventh and G streets NW and walk north one block; or exit the Yellow or Red lines at Gallery Place on Ninth Street. Proceeds from Taste of the Town go to Children's Hospital National Medical Center. Call 548-4034.