The world of wine is old, traditional and can have a lot of unspoken rules in formal settings. That is particularly true for the wine tasting event.
“Attending a wine tasting, for example, not only requires one to learn the appropriate etiquette, but also to perform the delicate juggling act of holding a wine glass, a pencil and a notepad.”
SCMP has a quick article that describes what you can expect at a tasting event.