It can be the simplest of potlucks, or an elaborate eight remove feast. They can be themed (such as a night in Istanbul's first coffee shop), or just a generic, 'lots of food' feast. Accompanying the food and drink is often entertainment in the form of dance, singing, music, board games, drinking games, or cloved lemons. Feast will often follow (or sometimes accompany) Court.
You are required to bring along feasting gear so you have something to eat your food off/with. It's also recommended that you pace yourself during large feasts or by the time you reach the fourth course, you won't be able to try any of the food in the last two courses!