At our cafeteria, they say that you're not allowed to take away food because then people can get (admittedly crappy) cafeteria food without paying for it, so disallowing it discourages begging. Perhaps it is the same there?

Elke from German class is going to Bryn Mawr (however it's spelled). If you were really curious as to how a modern all-women's college is, you could always ask her, if there's no one else to question?