It is a fancy restraunt where Stars (and other creatures) can go and dine. The food is high quality and expensive. Many stars love the fancy restraunt.... except the main star in the series, the Shadow Star. He has gone on record saying the food is garbage and way too high of a price, and that it can't compare to the cafe at the UFO.
Boo from BP8 used to work at the starstraunt. Orange Kirby was hired as he made the kitchen lit, and Boo was fired for dropping the food of customers on the ground.