A dog crate comes in handy in this situation, but if you can't use a crate, then try just using your dog's bed. When it is time for your dinner, tell your dog to “go to bed” or “go lay down” or whatever your usual command is to send your dog to bed. If you are using a crate, you may simply close the door so your dog cannot come out. If you are using an open dog bed, you may need to get up from the table a few times to return your dog to his bed until he gets the hang of this routine. If you are consistent in enforcing that your dog needs to be in his crate or bed when you are at the dinner table, he may eventually go there on his with no command needed when you are putting food on the table.

Cheers to a soon uninterrupted dinner!