What do you say when you are asked to say grace? 

"Grace."

How do the salt and pepper welcome all the guests? 

They say, "Seasoning's Greetings!"

What did the leftover turkey say? 

"Make me a sandwich!"

Which side of a turkey has more feathers?

The outside.

What did the turkey say when he bumped into the president?

"Pardon me."

What did Han Solo say to Luke Skywalker on Thanksgiving?

"May the forks be with you."

What do you get if you divide the circumference of a pumpkin

by its diameter?

Pumpkin pi.

My dog got into a fight with the Thanksgiving turkey.

He knocked the stuffing out of it.

Are you punny?

Here are a few lines you can use:

Y'all bready for this?

More rolls? You butter believe it!

I only have pies for you.

You think Thanksgiving dinner is done? You ain't seen stuffing yet.