Answer:
In the context in which appears, it would be accurate to infer that the "ambergris" is a type of scented material of some kind. In the context in which the word appears, many "romantic" things are mentioned: Candles of special wax, incence, perfume, etc. In this context, the ambergris is most likely something related to those things.
The "ambergris" is actually one of the world's strangest natural occurrences. It is produced by sperm whales and has been used for centuries.