You're Probably Sitting Down At The Dinner Table Wrong
There are a lot of weird, old-fashioned quirks of dining etiquette. Knowing what utensil to use (and when) is a heavy task. Using a napkin is harder than you may think it is. Heck, even knowing how to get up from the table to use the restroom or take an important personal phone call is convoluted. And yes, you're probably breaching a rule of etiquette when you do any of these things. You know what else? You're even sitting down at the dinner table all wrong.
Indeed, proper sitting etiquette begins before you even approach the chair. If you're in a slightly more formal setting, you never want to just plop down in any old chair. Chances are, your host has an idea of where everyone's place is. So remain standing near the table until you're told where to sit. You'll want to remain standing until your host sits down. Then, you will follow the host's suit and sit in your chair.
Once you're sitting, following the host's lead is generally the best practice. When the host puts their napkin in their lap, that's when you'll do so. Is a blessing being said? Even if you're not a religious person, bow your head in acknowledgment. Is someone offering a toast? Raise your glass and cheers along with the other guests.
There are also a few other ways you need to avoid being rude while seated at the table. Of course, sit up straight and don't put your elbows on the table while eating. For goodness' sake, don't check your cellphone at the table, don't talk with your utensils in your hand, and remember not to reach for food. Ask for it to be passed instead. Doing any of these things would be a serious table etiquette mistake.