"What do I do with it?" sounds more like a rhetorical question. "What should I do with it?" is a normal question.

What do I do with it? is not as polite. In certain situations, and depending on how it is said, it could come across as disrespectful to the person who gave it to you. What should I do with it? is less of a direct question. There is little chance that it could be taken as disrespectful. Really, though, the difference between these two replies is not large, but with the less direct question you are not putting the person who you ask so much "on the spot", so he would not feel as much pressure to come up quickly with a correct answer for you while he may have been engaged in something else.

Either is possible.The 'should' form would be the most likely response, but 'What do I do with it?' is also possible. As you know, the present simple is used for habits, rules etc, so ''What do I do with it?' would mean you are asking what is normally done with such a spreadsheet, according to company practice.

am înțeles. Mulţumesc!