It's a small late 18th century candlestick or taperstick.
Tapersticks held thin candles, usually made of beeswax or spermaceti, that didn't give much light but were used principally for melting sealing wax.
Because of this, tapersticks were sometimes referred to as tobacco or tea candlesticks.
Small candlesticks and tapersticks made of base metals and silver are reasonably common from the 18th century onwards but glass examples are found less frequently for the obvious reason that they are fragile.
There are cordial glasses for more formal drinking, wine glasses in seemingly endless capacities, short ale glasses, ratafia glasses and on top of all that, several glass candlesticks and tapersticks
, oil lamps and a lamp.