For future reference to people who may ask the question, this might help people know what fits where on Caravelle rails. From left to right (or right to left,) I'll number the slots 1-6.
The rear bench uses slots 1, 2, 5 & 6.
The captain chairs use 1+2, 5+6, or can be centrally mounted using 2+5.
The table uses 3+4.