That is so stupid. Your school administrator is a moron.
Anyway, there are chazal by when the stoned zecharia in the beis hamikdosh, that it happened because he talked to them “me’al la’am”, that is, that he in some respects talked down to them and that’s why they weren’t mekabel.
So you should say that you shouldn’t sit on the table because it might give an impression that you consider yourself meial laam, and would diminish your ability to give tochacha to your classmates and to school administrators.
I think that should serve them right.