Ok, I THINK I've got most of this figured out. As soon as you go into your game the game sets up a series of "save" files with the date and time. These will be, in your EA file folder, from 0 to 4 or 5. There really isn't anything apparent in there because if you remove every other save file from that folder, except that top bunch, and go into your game you won't be able to load a game. It isn't there.
What I did was this. Yesterday I removed all my save files from earlier date/time stamp except the most recent. Out of three games this left me with two games. I couldn't tell in the files which ones were which until today. I only played one family yesterday so that one had the latest date/time stamp. I removed all other files and went into game and my one family I'd been playing was there ready to be loaded with no other "save as" files showing. I left the game and removed all but the top few, newest, time files and then went back into game. My games were all missing and I could not "load game". My next step will be to put my game back in but remove the earliest time of that game to see if my game will be able to be loaded and played from where I left off.
Every time you save, or save as, a new file is created in your EA file folder so this can get pretty long and full. Eventually it MIGHT slow your game down. So if we know we can remove the earliest parts of a file and be able to continue to play that particular game it should save space and hopefully keep your game from slowing down. Now, I'm totally a non-tech person, so I could be way off base here, but that's what my fooling around has led me to believe.
If you look at the extended line of your files to where it shows how big it is, you will see they get bigger and bigger as you do or add more and more. Every time you save you are adding a new file instead of it just enlarging the original file. What I don't know for sure is, is it adding all that information over and over, like repeated back up files. So I removed all but two files for one of my games, one I didn't care if I lost, and went back into game and voila, the game was still there. So I deleted those removed files. I then cut the two files I'd left in and moved them to a folder with the name of the "saved as" game. Again, went back into game and lo and behold the game was gone. When I replaced those two files again, the game was back but with only two files instead of six. So now I have separate file folders on my desktop for all my various games and "think" I know how to keep the amount of files in the EA folder down to a minimum.
I'm hoping a tech savvy person can figure this out, see if I did it right, and maybe explain it all more clearly.