Can I refrigerate the stuff left over on the baking sheet?
Yes, it'd be safe to put the sheet in the fridge. But you might not want to if they're just plain rolls:


Refrigeration makes bread go stale faster, so you may not want to refrigerate your rolls at all.
It's important to get things airtight in the fridge, and often it's a pain to wrap up a baking sheet to be airtight.
If the coating on the sheet isn't perfect, and it collects condensation in the fridge, it might rust a little faster.
Baking sheets can be bulky and awkward in the fridge.


If you want to keep bread long enough that room temperature storage doesn't work well (more than a few days), the freezer is a better option.

On the other hand, if they're filled with something perishable, you'd need to refrigerate or freeze. In that case, you could use the sheet if you really have to and can wrap it reasonably airtight, but generally it'd still be easier to transfer to a bag or smaller container.