You mention table manners and my mind springs to different customs/traditions surrounding tea or coffee drinking in certain cultures.
Here's an article that talks about a few tea drinking do's and don't's

One on there I found most interesting is this one:
Linked Article wrote:
East Frisians have a unique tea ceremony in which pieces of rock sugar are placed at the bottom of a cup, covered with hot black tea and topped with cream or milk poured from a special spoon. Don't stir—the layers are meant to be enjoyed as is. Simply place the spoon in your cup to signal that you're done.
Some others I've heard of are in India when having tea in a shop with the owner, it is impolite to discuss business until you are both done. In [country I forgot] it's polite to taste the tea before adding milk, cream or sugar since you should taste it in it's purest form first.
To steal some more detailed facts from the
Chinese Wiki page....
Finger TappingThis custom is said to have originated in the Qing Dynasty when Emperor Qian Long would travel in disguise through the empire. Servants were told not to reveal their master's identity. One day in a restaurant, the emperor, after pouring himself a cup of tea, filled a servant's cup as well. To that servant it was a huge honour to have the emperor pour him a cup of tea. Out of reflex he wanted to kneel and express his thanks. He could not kneel and kowtow to the emperor since that would reveal the emperor's identity so he bent his fingers on the table to express his gratitude and respect to the emperor.
The bent fingers for knocking are technically supposed to be three to signify a bowing servant. One is the head and the other two are the arms.
It should be noted that in formal tea ceremonies nodding of the head and/or saying "thank you" is more appropriate.
Reasons for Serving TeaTo connect large families on wedding daysThe tea ceremony during a wedding also serves as a means for both parties to meet with each other. As Chinese families can be rather extended, and there may be one or two hundred people, it is entirely possible during a courtship to not have been introduced to someone. This was particularly true in older generations where the patriarch may have had more than one wife and not all family members were always on good terms. As such, during the tea ceremony, the couple would serve tea to all family members and call them by their official title. Drinking the tea symbolized acceptance into the family, while refusing to drink symbolized opposition to the wedding and was quite unheard of since it would result in a loss of "face". Older generations would give a red envelope to the matrimonial couple while the couple would be expected to give red envelopes to the unmarried younger ones.
To apologizeIn Chinese culture, people make serious apologies to others by pouring tea for them. For example, children serving tea to their parents is a sign of regret and submission.
To express thanks to your elders on one's wedding dayIn the traditional Chinese marriage ceremony, both the bride and groom kneel in front of their parents and serve them tea. That is the most devout way to express their gratitude. In front of their parents, it is a practice for the married couple to say, "Thank you for bringing us up. Now we are getting married. We owe it all to you." The parents will usually drink a small portion of the tea and then give them a red envelope, which symbolizes good luck. Another variant is that the bride serve tea to the groom's parents, symbolizing that she is to become a part of the latter's family.
As a sign of respectIn Chinese society, the younger generation always shows their respect to the older generation by offering a cup of tea. Inviting their elders to go to restaurants and having some tea is a traditional activity on holidays. In the past, people of lower rank served tea to higher-ranking people. Today, as Chinese society becomes more liberal, sometimes parents may pour a cup of tea for their children, or a boss may even pour tea for subordinates at restaurants. However, the lower-ranking person should not expect the higher-ranking person to serve him or her tea in formal occasions.
Additional coolio page about Chinese tea!