I have got some 1300+ Save files and the Clound only holds 800 MB. How can I do a mass delete of save files? I started doing one at a time, but that will take forever as they go back to January. I have been unable to Synch with the Cloud, now I know why.

The cloud sync is checked when a game starts and when the game's process ends. So start the game, cloud sync will fire up and see that the local files are up to date, while the game is running alt-tab out, go to the saves directory and manually delete them (or those you want to delete). Then exit the game, the cloud syncing will see the remaining saves as those it has to update, and should update normally.
It would help to mention what game you want to delete the saves for, so we could give more info about where they are stored. Be aware that some games also have a database for the saves, not just the saves themselves, so manually deleting saves may be a bit trickier.

Are you talking about one game or savefiles from several games?

Sorry About that. Playing The Witcher 3 GOTY. I started the game, and clicked to continue, then once the game was up, I them opened the Load window and started deleting them. I also deleted most on a folder that was in Documents. Cloud was still showing a little over 1000 Mb of of files that I can't find. It was over 1400 GB when I started. I have played through it several times, and if that is what you mean by several games, then I supposed it would be, but the drive was wiped. I had played through TW3 a couple of times, then Got TW3 GOTY and had both installed. The originla game is in my Library, but NOT installed to my Computer. Geez, I am thinking it could be looking at those files and I have no idea of where they may be.

No, with several games I actually meant several different games as until now you did not tell us that you were only talking about TW3. Savefile location for TW3 is this:

C:\Users\USER\Documents\The Witcher 3\gamesaves

Yeah, bit short on the info. Sorry. No, just playing TW3. I thought I had lost everything and reinstalled TW3 GOTY. It showed 10 May 2017 as the last save ( Sinced ). The up to date save was in my trash can, so restored it. That is all I have as far as ingame saves showing and also in my save game folder in Documents, but Cloud is saying there are 1036 Mbs of saves. I am wondering if it has anything to do with the Original Version that is in my Library and played through at least once. Even dumped my Trash can to be sure it wasn't looking in there. Oh well, At least I haven't lost my progress. I have a bunch of stuff on Steam and save like crazy and have never had an issue.