"Tcheou-Li," "I Li," and "Li Chi," were written between the second century B.C. and the first century A.D., from much older sources. The "Li Chi" in particular has specific sections on table manners.
Teaching children manners by way of riddles and stories have been done for millennia. Hesiod advised about 2,700 years ago, "At the abundant dinner of the gods, do not sever with bright steel the withered from the quick upon that which has five branches."
Meaning, "Fingernails are not to be cut at the table." Didactic poetry has existed since the time of Ptah-Hotep's "Instructions," written for his son which date to about 200 B.C. but were copied from another book 500 years before. A whole new generation of manners books arrived in the twentieth century. Emily Post's "Etiquette in Society, in Business, in Politics, and at Home," appeared in 1922.
She was careful to remind her readers of the tradition of civility by writing, "Best Society is not a fellowship of the wealthy, nor does it seek to exclude those who are not of exalted birth. It is an association of gentlefolk, of which good form in speech, charm of manner, knowledge of the social amenities, and instinctive consideration for the feelings of others, are credentials by which society the world over recognizes its chosen members." When her book was written, she thought it would be purchased by the upper class, but it wasn't true; they didn't need it.