Meal-time routine

Question
should I close my dog's crate door at meal times?

Answer
If the dog is in the crate to keep it away from the table while you eat and you need to to keep it in there, yes.

If you are feeding the dog in the crate, you don't need to unless there are other dogs or something to distract it.  I seldom feed the dog in the crate unless we are dog sitting and have extra dogs in the house.  Our daughter has 3 dogs and she shuts them in the crate to eat.