More Tables (Things) or more Querys?

Hello! I’m new in Bubble and I’m very excited playing with this great tool. But I have some questions about Database section. This is one of them: what it is better (more optimal) to obtain accumulated data, have them in separate tables that you would have to update every time a basic data is entered or not have those tables and do the calculation on the fly each time request the information by the user? Another question: the User thing, is a “normal” table or it have some kind of privilege?

Thanks