It means instead of playing, they make you sit and do some homework
"Out to lunch" means that you have left your office or desk and have gone to eat lunch. It can also be a figurative way of saying someone is not really paying attention. The image is of their mind leaving the body and going off to have lunch.
He probably likes you and is trying to get your attention by sitting by you every day.
You can play sometimes. There is recess and lunch. However, if you are in class, you should be paying attention and trying to learn instead of playing.
Join him at lunch. Find out where he lives & maybe walk home together. Invite him over.
"Out to lunch" is used both literally and figuratively. In many cases, particularly in the business world, individuals will leave a message at the office stating they are "out to lunch" - they are away from their office around the noon hour for the express purpose of eating lunch. However, "out to lunch" has also acquired a negative slang use, meaning "he's not mentally present", "the individual is not engaged in the conversation", etc - it often carries the implication that the individual is either lazy or is incapable of focusing his/her attention on the issue at hand.
have lunch
We did not take our lunch. We have not had our lunch. We have not taken lunch.
What did you have for lunch. It makes much more sense than what did you had for lunch.
Exit to lunch
The past tense is had lunch.
Unless your lunch is literally running from you, it is "go to lunch."
Breakfast and lunch were . . . "