It is an amazing work, to be sure.
As for the whole concept of the lectus tricliniaris, I just don’t get it.
I have seen movies in which Romans are depicted as reclining to eat. They usually prop themselves up on one elbow. Cannot imagine how else one could eat while lying down. And I cannot imagine why such a position would be favored over sitting as we do.
You may prefer sitting, as do I, but we ain't teens with a pizza and movie channel.
/johnny
Maybe it’s was a holdover from a nomadic past, as that is typically how Middle Eastern nomads ate even into modern times, lying on the floor, propped up on pillows and whatnot. It is even suggested that Christ and the apostles ate like that at the Last Supper, as the beloved disciple is described as leaning or reclining on Jesus’ breast.
The practice seems to have come from the Etruscans (although the Etruscan men ate in the same room at the same time as their wives, unlike the Republic-era Romans and the Greeks). Boogieman’s suggestion that it started centuries earlier among nomadic ancestors looks pretty plausible to me.