This is a good question, but I'm thinking that is not exactly how it works. I know it syncs documents & other things across devices, but it's not clear to me that you can delete a file on your iPad and expect it to not get deleted everywhere. You can backup your iPad there (and restore from there), and use iTunes Match to bring down music. AFAIK, it does not work like Google Drive, Skydrive, etc, in that you can just copy files to it from your PC and they will live there, letting you get them whenever you wish. For example, since I started typing this, I opened up my iCloud account in a browser on my PC. Then I went to my iPad and opened Keynote. I could see all of the files on my iPad in my iCloud. I then created a new file on my iPad in Keynote. I went to my PC and did a refresh on iCloud. Then, my new file shows up in Keynote. Then I went to my iPad and deleted that new file I had created to test this. Then I went back to iCloud on my PC, did a refresh, and the new file disappeared. Never did I get a prompt saying if I wanted to keep the iCloud copy...it just removed it.
I'm not claiming to be an expert on iCloud, but I'd be careful about thinking that I can delete a file off my iPad because it is backed up on iCloud. You might just be deleting that file everywhere.
Maybe some others will chime in on this 'cause I'd like to know the exact answer too.