wp_PO

wp_PO_plugins is the table name that plugin organizer creates. How you clean it up depends on the version you are running. If it is an older version there is a setting to keep your settings when the plugin is deactivated. Turn that off and deactivate. Then the settings and table will be removed. If it is a newer version you need to remove the plugin through the wordpress admin and it will remove everything that was created by plugin organizer. You can also manually remove the databse table without affecting wordpress. But that leaves some settings in your wp_options table.