"Found at an estate sale. Most of the other items at same sale where dated from 1950s to 80s. Measures 9″ x 4″"
A: "It has the hole design of a Cribbage board."
"They're oil absorbing pads and since oil floats on water the tube is there to stop the oil from flowing while letting the water pass under it"
I had to visit reddit to look it up... I feel dirty.