I use a plastic shopping bag, with a steel clothes hanger bent over the protruding base mounting bolts. It holds a lot of spent primers and catches those that want "fly".
It holds a lot of primers and other bits of whatever collects on the bench, such as the cleaning/lube cloths I wipe the presses down with after I'm finished.
Kjohn, I like your tray, good work. Looks much neater than the bags I attach.