The fun is nonstop sophomoric at this Dallas-based chain’s Excalibur outpost, where the waiters pull silly tricks on unsuspecting customers, and make them wear dumb hats to boot. Food here is better than it probably needs to be, especially the Cowboy rib-eye steak and the drunken shrimp cocktail. At dessert, the Mile High Peanut Butter Pie’s a doozy. Inside the Excalibur. 597-7777. Food served 11 a.m.-midnight Sun.-Thurs., until 2 a.m. Fri.-Sat