The table piwik_pog_action should be included in the “Delete old visitor logs from database” function.
On my System piwik_pog_action is the biggest table with 831 Mb.
piwik_log_link_visit_action is only 481,6 Mb and piwik_log_visit is 170,1 Mb.
My settings:
Delete logs older: 30 Days
Delete Logs every day