In the eighties, our phone rang a lot during dinner, something my mother didn't love, though she saw the necessity in my dad's line of work. He was a real estate agent, and a lot of people needed him outside of their own work hours. (After all, you usually have to have a job to buy a house, so ditching work to look for one isn't the best plan.) But we still had rules about talking on the phone during dinner, and they even applied to Dad.
With changing lifestyles and meal times, as well as seriously ramped up technology, the rules have changed, but perhaps not as much as we think. My parents' standards for phone communication at the table are the same ones we use today, even if we don't have a fancy box to hide our phones like the one in the above photo.