My grandfather 97 is sleeping constantly and not eating much, is this normal?

I'm sorry, but he may be nearing the end. I'd contact his doctor unless he's in a care facility. At 97, I'd say it's "normal," but his body is shutting down. A doctor should consider if there is infection or something going on, but he may just be wearing out. It sounds like a peaceful end if that is what is happening. It doesn't hurt to check with the doctor however.
Take care,
Carol