Ah, the Sean Connery accent PasteOff jokes just keep on rolling.
Matt noted that PasteOff is a "huge memory hog", using 12 MB from a cold start and 24 when noodling around after a while.
It's working set bloat! It's not my fault!
If it bugs you (and it's starting to bug me more now, as I'm constantly watching the number), you can actually reduce memory usage by getting an image onto the clipboard, displaying the preview window, and then minimizing the preview window. Watch that number drop!
Rick Strahl covered this before, but I'd rather just leave the application to its own devices, and let Windows reclaim it on demand.
BTW, I tried cheating by setting the shortcut to run Minimized, but it didn't pan out, there's no form to minimize most of the time.