Your toddler should be able to learn the basics of table manners: to wash his hands before each meal, to eat with utensils instead of his fingers, to say please and thank you, to keep his voice down. And be firm and consistent when you’re teaching him these skills.
Sometimes toddlers forget the rules — for example, eating with their hands because it just seems like a faster way to get the food to his mouth. In that case, hand him his spoon as a reminder of what is and isn’t okay.
He learns, for the most part, from watching you. So, if he sees you enjoying meal time, odds are good that he'll enjoy it too.