By chance, I already realized that there is another way to fix this, without adding extra columns/rows. This is because I have already built tables where this does not happen. But I still don't understand how I can do that.
Well, I know the steps necessary to achieve this, but I can't do it every time. Or rather, I couldn't do it manually.
When I create a table using an Excel file, the table no longer suffers this problem. But, I still don't understand what information Excel leaves in the cell copied, so this doesn't happen. If I discover how to do this manually, I will share.