In the Work Bench you can select individual records or categories by checking the box next to the reoord or category.

Depending on the task at hand, you might select to "remove" or select to "keep" an item. After you select items on these criteria use the Edit Menu to "Create Sublist from Selected" or "Create Sublist from Unselected". You can select the first N records by clicking on the "1st N" label and entering the number of records to select.