A few years ago (before I was married) I started a family tradition of setting a place at the table for the Unexpected Guest. I'm not sure where I had heard it from but at the time it seemed like the thing to do. It's a wonderful symbolism of Christ coming and being ready for Him when He does. However our table barely fits the 6 of us with the kids sitting at a plastic kids table in the kitchen. We've taken this tradition to just having enough stuff to set out for the Unexpected Guest. I make sure there's an extra fork, spoon, knife, plate and napkin set out should the Unexpected Guest arrive.
My mother of course thought, and I bet if truth be known probably still thinks, it's a silly thing to do. To "waste" dishes. Then, a year or so after starting this tradition, when there was still room at the table, my grandfather showed up unexpectedly and was greeted as though we knew he was coming and showed him his place at the table. Every year I'm reminded of our unexpected guest showing up.