My grandfather just passed and every night as I shut my eyes to sleep he's there does this mean anything?

If you were close to your grand father you probably miss him, and that is all that you can really think about. So while you are sleeping you are still thinking about your grandfather. In short you want him back and your dreams are showing a sign of wanting. For example my mother was going to have a baby boy and I was thrilled since I was the only boy in the family with four sisters. Unfortunately the baby died and my mom had a miscarriage. I was devastated and for the past 3 years all i could think about was my dead little brother and for all those three years he appeared in my dreams. Sometimes as a baby, other times as a older child, and somtimes a full grown man. But all the same I had these dreams because I wanted my little brother. You are probably going through the same problem.

If you weren't really close to your grandfather it might be that you are feeling guilt that you didn't spend as much time with him.

The mind works in mysterious ways so these might not be the reason but this is the closest answer I can come up with for now.