Most of us picked up the correct etiquette for eating from our parents (don't put your elbows on the table, William) or from our contemporaries (which way to pass the port). I guess very few learnt from Books of Etiquette.
Yet, the first book on Etiquette in England, although written in verse and in Latin, dates back to the early 13th century, possibly to the reign of King John. It was written by a Daniel of Beccles of whom we know virtually nothing. He was possibly a courtier in the court of King Henry II. He was possibly also, but no evidence other than his name, a Jew. After all there were many Jewish communities in East Anglia living and working in Norwich, Bury St Edmunds, and Colchester. Moreover Daniel wasn't a common Christian name in England until the Puritans adopted names from the Christian Old Testament in the late 16th century. Finally it is easier to imagine a cultured Jew writing such a work than an English layman of the period!
Some of his advice is startlingly modern, and other certainly not:-
Say thank you to your host
In front of important people, do not openly excavate your nostril (in the 1950s my Prep School in Bristol had a master who wrote on punishment cards the crime of 'excavation of his nose').
Don't put your elbows on the table
While food is hidden in your mouth, let not your tongue not minister to words (Don't speak with your mouth full, William)
If you wish to belch, remember to look up to the ceiling
Guests and servants should not urinate in the dining hall, but the host may!
Daniel's advice goes beyond table manners;-
Do not attack your enemy while he is squatting to defecate
If there is something you do not want people to know, do not tell it to your wife (very non 2020)
If the wife of one's lord makes a sexual proposition, feign illness!!