The work centers to show on the display and the max amount of items to show for the work center.
The reason to limit the max to 5 or so, is if you have more than 1 work center on a display and the first work center shown has enough items to fill the display, you will never see the second work center. Limiting the list to 5 or 10 will prevent this.
If you do not enter a value for max shown, the default of 5 will be used.