1. First I would try to put a filter called "Pre-defined Filter" for "Log Type Filter". This will remove non-traffic logs such as control, system alert etc..
2. You can try to copy this widget to a view. You can perform a drill down from the view (you might need to remove from the query the section for "...AND Action:"" because it won't find matches for this.
3. If those logs appear to be unimportant, you can select "Remove empty values" from the action field in the widget field.
Amir Senn
Kind regards, Amir Senn