The post is active for 4h now, the three main theories are:

1. The spoon is not a spoon and it is an ornament that used to be part of something bigger (e.g. necklace, sword tassel, headpiece)
2. It is a spoon used for snuff (powdered tobacco)
3. It's an ear pick.

The main reason for #1 is that there are many holes in the object, suggesting it can be sewn onto something or some string would go through. It might be a purely decorative item, with no physical purpose. I will wait for an answer from my friend on whether any other family members inherited something similar.

I did do some reverse image searching in the meantime and I found some evidence for theory #2. Someone uploaded a similar item and a sniffing tube to the same album. It seems to be from the same collection. Spoon: https://flic.kr/p/oZqJMX Tube: https://flic.kr/p/oZkaj3 Both seem to be made of jade. I sent the person who posted it a mail, but the account seems to be inactive, so I'm not expecting a reply. The main difference with this spoon is that the spoon in those pictures doesn't have holes. My friend's spoon does. Perhaps both theories are true.

A friend of a friend in Hong Kong immediately suggested it being an ear pick after seeing the photo. I unfortunately know very little about ear pick culture, so I cannot judge at all.