Not to be confused with auditoria, which is the plural of auditorium.
An auditeria is a combination cafeteria and auditorium. As such, it has both tables for eating and a stage upon which one might perform.
Most dictionaries (in fact, every single dictionary I've looked in) do not consider this to be a real word; I first discovered it in American School and University (a fine upstanding publication), and have found other references to it on Google. Apparently it is a new and innovative design that is sweeping high schools across the nation (the USA, that is). This falls under the buzzmeme of Multi-Purpose Spaces, which is also sweeping the nation.
As far as I can find, cafetorium and auditeria are exact synonyms, except for the confusing fact that some schools have both a cafetorium and an auditeria.