“请不要趴在桌子上”怎么翻译呢？

Don't lean over the desk.

参考：Sit up, children! Don't lean over the table!
坐直，孩子们，不要趴在桌子上！

please don't bend over the desk
please don't lay on the desk

don't lie on the table/desk please。

Please do not bend over on table

please don't lie on the table.