Why they put this food menu with prices on your cabin for their room service?
I don't know what you saw on the Adventure Of The Seas. My recollection is the room service menu only charged for things such as party platters and bar purchases. The sandwiches and hamburgers were always "no charge".
Regardless, if you look here
you can download the current RCI room service menu which shows all the items that are included in your cruise fare. These items will have the service charge added if you order them between midnight and 5am. Drink orders will not have the fee assessed.