I'm trying hard not to offend too many people here in small-town France with my heathen American dining manners. So here are some of the local quirks I've observed along the way.
When I came to breakfast and found a bowl at my place, I quickly learned that it wasn't for cereal or yogurt, but for coffee (with or without as much hot milk as I desired). And I thought my coffee cup at home was large!
And the sliced french bread (toasted or not) is only to be eaten after being dunked in the coffee (we're still talking breakfast here).
Speaking of french bread at meals... Those paper tablecloths on each table aren't only to make clean up easier, they are to be used in place of side plates. Do NOT break your bread over your plate, instead tear it apart over the tablecloth. This lesson I learned the hard way: When the waiter cleared my dirty (because of bread crumbs on it) plate, they were then unable to serve me the next course because there was no plate. Oh, the consternation and confusion which ensued!
Here is the lesson which has been most difficult for me: hands must be kept in sight at all times. They must never be allowed to disappear below the table top because...oh the imagination boggles. Putting elbows on the table is perfectly acceptable and forearms too. To make space for the waiter to reach in, it's okay to lean back with arms crossed. I've seen feet do all kinds of interesting things below the table, but hands down there are a no-no.
Fortunately, I am not a picky eater. There are a lot of absolutely amazing small restaurants in rural France, where I walk in and they serve me what they prepared that day. There are no choices offered, I simply eat whatever they decide to bring out to me. So far, so good - no brains or stomachs or noses yet. The raw egg in the shell was a surprise though.