the way you eat your food, or the socially acceptable way to eat your food, especially when eating a meal with others

Your table manners are awful - don't you know how to use a knife and fork? 你的吃相太难看了——你难道不会用刀叉吗？

I don't think he ever learned table manners at home. 我觉得他家里从没教过他餐桌礼仪。