Sausages are served on plates.
John the Baptists head was delivered to Herods Missus on a plate, Pontius Pilate washed his hands in a plate like bowl and the harlot drinks the blood of the righteous in Revelation out of a cup shaped plate.
So since everytime a plate is mentioned it is a bad thing and sausages are served on plates, JWs can't eat sausages.