If one finishes shemonah esrei and people behind him are still davening shemonah esrei may he take his 3 steps back if there is a table where they’re davening if not what should he do
A table is not enough to permit walking or crossing in front of a person davening shemona esrei because it is not high enough, since it has to be to the high that he wouldn’t be able to see you passing by. The reason is because crossing in front of him will disturb his concentration. There are times when he is allowed to take his three steps back depending on the circumstances. For example, if he can’t wait to take the three steps back, and he isn’t directly in front of the person davening, then he may take his steps to the side, away from the direction of the person. I am inserting, something that I wrote on crossing in front a person davening, where the halachos are discussing in greater detail.
M:B 102-2, 18.