At home in France: French country and city living
Your wonderful vocabulary tips of course always teach me something new about French, but you might be surprised how often they make me think anew about English as well! Here the connection (obvious once you think about it) is with a "clean slate"--a small chalkboard, capable of being "wiped clean", for the temporary storage of debts, school demerits, etc. Little squares of slate, cheaper than the classical wax tablets, were used since medieval times in the schools.Now all I have to figure out is the British "buying something on tick" and the American "put it on my tab".
Thanks! I have no idea for the phrase "buying something on tick," but I would venture to say that "tab" might be short for tablet.