The attached word document and Tableau 8.1 workbook demonstrate how to set up and use the built-in audit tables that ship with every Tableau Server installation. The workbook is connected to my local install. You will want to edit the data connection and point it toward you actual Tableau Server installation - specifically, the IP address or hostname of the machine running the postgres repository process.
Like most things that I do, this is a work in progress and may contain incomplete or inaccurate information. If you see anything glaringly bad, please let me know and I will update the contents. Enjoy!