Elbows on table kills the table fairies

My grandmother used to tell me that if I put my elbows on the dinner table that it would kill the table fairies. I don’t know why, but I never really questioned this bizarre adage. Now that I am older and have killed a hundred thousand table fairies, I decided to investigate how this aphorism came about and why it was ever such a faux pau to but one’s elbows on the table in the first place.
I found several explanations as to why putting your elbows on the dinner table has been frowned upon for centuries. One is because people’s underarms used to have perpetually bad odors and airing out their stinky pits while others are eating is not cool! Others say that it is slovenly and lazy. I also read that people used to dine at picnic-esque style tables, so placing your elbows up on the table would crowd your neighbors and make less room for others to sit down. Also, tables back in these days were not structurally sound so the excess weight of one’s elbows on the table could break or tip it. Nothing in my research pointed to the origin of table fairies. In fact, the idea of killing table fairies was only mentioned two other times in the results of my google search. So, either (1) my grandmother is crazy, as anyone in my family can attest to, (2) adults came up with this to avoid lengthy explanations to children, or (3) table fairies really exist and we have been wholesale massacring them for centuries.