I have read several times that the best protection for your credit cards is to never let them out of your sight. It doesn't work that way in restaurants.They take your card and disappear for five minutes before it is returned for your signature. It can be compromised while out of your sight.
I contacted the Utah Restaurant Association a couple of years ago and suggested that servers bring card readers to your table for the transaction. I pointed out that almost all of the restaurants in Europe did it that way and that your card was never out of sight. They did reply, but doing it that way was not practical at the time.
OK, but that was then and this is now. Why can't it be done? Transactions would be faster and your card secure.