My Jasper kitty LOVED ham. It was nearly impossible to eat it around him, because he'd constantly harass the humans for a bite. I didn't give it to him very often, but it really came in handy when he became diabetic. Sometimes he wouldn't eat his normal food at insulin time, and I couldn't give him the shot until he ate something. Ham always came to the rescue!
I asked the vet about it once, and he said that it's not good for a cat to eat too much ham, but once in awhile is okay (and it was better for my cat to eat the ham and get the insulin than to not get the insulin at all).
