what is "Joaks upon Joaks"?

X upon X = may layers of X, i.e. large number (or much) of X. Example: pleasure upon pleasure = much pleasure. He told lies upon lies = he told many lies. Jokes upon jokes = a large number of jokes. Jokes is the modern spelling of "joaks". Full title "Joaks upon Joaks, or No Joak like a true Joak".