They look a lot like the temporary folders I have in AppData\Local\Temp or in \Windows\Temp
I don't think there is any danger in deleting them altogether (they're empty and a few months old) But you should make sure that no other application (or service) is using your Document Root Folder as a Temp folder (or a garbage bin).
There are the temp files that are created before the QVW is named. There shouldn't be a problem deleting them, but it would concern me that they are there. I would keep an eye on it and if you start seeing them again, contact support.