If I make different files for every graph, how can I combine them in a single Tableau archive?

Hi Gonzalo!

Thanks for reaching out!

1) Open the workbooks you wish to combine.

2) Select the worksheets in the source workbook that you want to copy to the main workbook. 

3) With all worksheets selected, right click on any of the selected tabs, and then click Move or Copy.

Hope this helps.
Best,
Martin