One of the first dinners I went to in Italy 40 years ago was something similar to the polenta on the "spianatoia" in the photo above. It was a thank you dinner offered to the entire Tacconi family by the farmers who worked their fields. There must have been about 20 of us around a LARGE hand-hewn "spianatoia" with an enormous amount of steaming homemade polenta cooked slowly (no pre-cooked corn meal back then) in an enormous copper pot hanging in the large fireplace over the raked coals and served with a thick, tomato-based, pork meat/sausage sauce, with small hunted birds cooked in the sauce as well. The rural tradition, to keep things simple, was to eat FROM the board, slowly progressing toward the center.
It has been about 25 years since I have been served polenta in this communal way! The change however, has been very partial: while the polenta is still served on wood, either large or individually sized and rarely hand-hewn anymore, each person spoons his serving onto his own dinner plate and eats it from there as you can see we did the other night at a dinner with friends near Assisi.