The servers bring you drinks, explain how things work, and bus the tables. You get your own food. When you are seated, they give you a card which is stamped each time you pick up a food item. They add the 10% gratuity when you pay at the exit.
10% is considered an appropriate tip for a server who only does drinks. I don't know if they will remove it if you are unhappy with the service.
By the way, we found the food at the Pepper Market to be the best of the moderates' food courts, by a significant margin.