Do dementia patients get food cravings?

Like Grandma1954 said, there really is no "normal" with dementia. My husband used to watch a lot of the shows on the Food Network, and would call me in the room when he saw something he liked and would try and tell me that that was what he wanted for supper.
I think the funniest was when he, after not ever eating fish since I met him, decided that he wanted fish for supper one night. I of course obliged, and from there until shortly before he died, wanted fish on a regular basis.
It cracked me up, because I remember us going to a seafood restaurant years earlier(as I am a seafood lover)and my husband ordering the only chicken dish they had on the menu.
Because of his late in life love of fish, my son and I on my husbands first birthday after his death, ordered in seafood in his honor.

My mother ate exactly the same food items (boiled potato, ground round patty, applesauce and butter) every day, for years and years and years.

No problems with nutrition, just habit. When she entered residential care, she ate what she was served.

I don't think there is a "normal" for dementia.
Just like a kid gets on a kick for a particular food, piece of clothing, TV show anything.
I think with dementia a sense of familiarity is comforting to some extent. There is security in knowing how to eat a food, how it is going to taste. Same with watching the same TV show there is a pattern that is comforting.
To make it easier on you when preparing a meal either do not offer more than 2 choices or just make dinner and serve it. If he does not eat all of it or picks at it don't pressure to eat all of it just clear the plates when you are done and later offer a snack.
If you notice that he is gaining or loosing weight that might be of concern and check with the doctor.
For the most part don't get overly stressed.
Keep the meals as balanced as possible with a variety of foods.
You may also find that a larger meal in the middle of the day is easier for him, or even forego larger meals in favor of many smaller "snack" type meals.
If breakfast in the past might have been a few eggs, toast, juice and some sausage or bacon break it up to an egg at 8 am, toast at 10 am, some bacon or sausage a bit later. Before you know it you are serving lunch the same way and rather than stuffing himself at one time he has smaller portions over the day.