I'm going to let my 3 year old son eat his ice cream on the restaurant's playground area
Are there other kids eating near the playground?
These other children act like savages act.
You should be sure that the playground has a table or chairs that your son can use. This will help prevent an accident because it could be dangerous to eat where many kids are playing.
I'm just letting my son eat some food on the playground. I have to do something so he won't act like a savage.
I understand that sometimes kids only will behave if you placate them with treats like ice cream. If having ice cream is the easiest way for them to be civil at a restaurant, then I think that's okay as long as you keep an eye on them.