Having a screen in a restaurant he's not a bad idea and like you said there are times when people might have to wait for their turn before they can make their order but like I said previously there is this classic beauty having a TV gives your office or environment.
It is not in all businesses that is necessary for you to have a television installed for your customers to make use of but in something like a restaurant or hospitality business like hotel, you must have television installed so that your customers will always make use of it for their relaxation.