The first coasters were designed for decanters or wine bottles, so that they could be slid (or "coasted") around the dinner table after the servants had retired.  The Victorians would also use coasters for drinking glasses, these were most commonly made from silver plate or silver plate and wooden bases.
 
Here we have two French coaster made from ebony with hand embroidered decoration under glass.
 
Dimensions:
Oval 22cm x 16cm
Round 16cm diameter