Errors and warnings can be filtered by their type.

Click Filter by Type to select and unselect the types of warnings and errors that are shown in the list. The pull-down will allow you to select "Show All" which will remove all current filters and show all rows that are not hidden, and the "Filter All" selection will filter all types, temporarily removing everything from the table. After using the "Filter All" command it would then be easy to target an individual error or warning type from the pull-down to show.