Translation:See you later in the cafeteria!
I think both "at the canteen" and "in the canteen" would be accepted. If the speaker regards the canteen as a spot, he/she would say "at the canteen" (not the library, not the entrance, but the canteen) while as a place with certain extent, "in the canteen" (anywhere inside the canteen). Posted on Nov. 19, 2017.
In English, "later" and "in a while" ( 一会儿 ) have different usages when it comes to lengths of time. "In a while" or "in a little while" is typically used for short amounts of time (minutes or under 1-2 hours) while "later" is used for longer spans of time (hours). We wouldn't say "later" if we meant 10 minutes or "in a little while" if we meant 12 hours.
Is "later" a good translation of 一会儿 or should it be "in a while" ?
Usually "in a while" is a better translation of "一会儿".
However, it's not absolute, and here it seems that the speaker and listener understand exactly when they'll see each other again "in the cafeteria", so to my mind it's not crucial to be fastidious with word choice, as the context is enough to make it clear.
I'm comfortable with my sense of this based on the context and my previous immersion experience, but of course defer to native speakers. Perhaps one will comment here, but for now here some Chinese native speakers discussing "一会儿" elsewhere on the internet:
A couple of them that say 一会儿 could be hours (and one even says days).
Language is about communication. If you don't understand the proper meaning or use of a word, then it has the potential to cause confusion and conflict. "I'll see you later" and "I'll see you in a moment" are not interchangeable when two people are planning to meet each other.
过一会儿 (guò yī huì r) means "later" or "after a while."