6 out of 11 - 90% guessing.
I got the Spain one right, but wondered how accurate it was.
Got the potato-cutting one wrong because I based my answer on personal experience. Glad to here it’s obscure.
The right/left-fork one got me as well. Can’t remember what else I got wrong.
So I guess I’ll only embarrass myself about 1/2 the time in international travels.
:dubious:
GT
8 out of 11 - let’s hope I’m never served fish in Poland.
Regarding the potato thing, I was told by my Grandpa to never use a knife on potato dumplings. The explanation he gave was the same the site gives, but I’m not sure if it really is an etiquette question or just a quaint custom.
7 out of 11. I got both the England and Scotland ones wrong, despite being English!
I got 7/11.
I got the Chinese one wrong, answering that it was okay to finish if it was rice; the Spanish table one wrong; the Polish fish one; and the Scotland lunch aka dinner one. But I thought the Polish, basing on a folk legend and the Scotland based on local descriptor of a meal were not exactly questions about international dining etiquette.
I got them all. 
I guessed on the Spanish one. Even though I’m Polish (well, my parents were born there), I made an educated guess on the Polish question. I never heard that superstition, but it sounded very Eastern European. There’s a similar one where if you light your cigarette with a candle, a sailor dies. I’ve heard this in Poland, Hungary, and Croatia.