Growing up, I was always taught that unless you are using a second piece of cutlery (always a knife for me) your left hand should be placed gently in your lap. Ahh, the British trickle down remnants of growing up in the Commonwealth… But as soon as I lived abroad, I realized that other Western cultures do not subscribe to this style. Most European cultures will have both hands visible at all times. Take note the next time you have the opportunity. Who is right? Both are.
Since a good portion of my life is spent straddling both sides of the Atlantic, I now lean into the Euro way of hand placement at a table. Obviously no elbows.