I have some tables with columns that I need to join/copy to another table, in case an attribute table. I was using join but I realized that it would be a better solution to add new fields to my initial table (attribute table) and then fill those fields with the columns that I need from the other tables than to join that tables into my initial table. Is there any tool that does that? Copy a column from one table to another? My problem is to distinguish the columns, I want to have specific names for each column, therefore I was thinking about create the fields and then fill them with the data from other tables.
Try this... Join the data to your layer making sure you're only joining the fields you wish to join.
Once that is done, export the layer to another copy. Your joined data will follow. This way you have your original layer and then another one with the joined information. It should be quicker than having to manually or programmactically copy data from your joining tables to your layer's attribute table.