Theyāre generally referred to as āspoon restsā, but you could use them for things like lemon pieces for squeezing, small snacklets, nibbles and such. Not for cigarettes, I think. Teabags is also a possibility but we donāt know the date for these coasters and the first commercial teabags didnāt appear in America until 1904.
The seller says theyāre marked āsterling, makers mark: crown, B, Lion, and 4329ā (on the underside of the rim). Iām doubtful whether the marks are being read correctly and the picture provided is unhelpful:
Are yours marked?
I have no idea what the WHC, MDAFU and ā30 yearsā or ā35 yearsā is all about, but obviously a custom engraving for some organisation and not related to the maker. Unfortunately, that detracts from their value.