study hall

from The American Heritage® Dictionary of the English Language, 4th Edition

• n. A schoolroom reserved for study.
• n. A period set aside for study.

from Wiktionary, Creative Commons Attribution/Share-Alike License

• n. A class period, usually in boarding - or high school, where students are afforded the time for independent study and homework assignments, as part of the curriculum or after hours, the last notably as a punishment called detention.
• n. The classroom or other school hall used for such a purpose.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• n. a period of time during the school day that is set aside for study
• n. a classroom reserved for study