You can play a movie in your restaurant.
However to legally play a movie in a restaurant or other public place you need to purchase a license to legally show the copyrighted movie and content in public.
A Motion Picture Licensing Company offers unlimited licensing for restaurants and the cost is based on the size and type of the business.
However the cost of a Motion picture license to show movies and copyrighted content around $315.00 a year.
A friend of mine has a restaurant though and has televisions on the walls and will play movies that are streamed from places like Hulu, YouTube, Roku etc and he doesn't have a license.
But it's possible for someone to report you as you never know who is coming in the place.
It's not very likely that you would get reported and as long as you're not charging admission for the movie to be played and watched then you should be okay.
However having a license to play the movies is a good thing which can save you lots of money in possible legal fees should you get caught and sued.