The Audit Log feature is not really important unless you are using the program on more than one computer on your LAN (Local Area Network) with a shared database connection - or you have the program installed on a single computer but multiple users in different roles or without different accounts are logging in at different times.  In these two cases the Audit Log available to only Admin accounts can be useful.  You cannot delete log file items from within the program.  It is intended to track any entries that might have been changed and should not have been.  You can filter the log just like other grids.  By person logged in and so on.  The List View is shown below.

When you double click a row you can see more details of what was changed.