Tea time doesn't necessarily mean that one will drink only tea or any tea at all. It can refer to snacks and its meaning differs by the historical social class structure.
Greetings occur with a strong handshake.
Touching during conversation is frowned upon, as are public displays of affection and staring.
When invited over to dinner, arrive on time if you are in Scotland or Wales. If you're in England, arrive 10-20 minutes late. Keep hands on table during the entire meal, and the meal is over when the host folds his napkin.
In business, punctuality is very important. In older companies, connections are the most important and prevalent way of hiring. Meetings are also scheduled far in advance and presentations delivered must be detailed.

https://www.cia.gov/library/publications/the-world-factbook/geos/uk.html (Majority of information)
https://joshuaproject.net/countries/UK (Ethnic and religious data)
http://www.citymayors.com/gratis/uk_topcities.html (City population data)
Wolfram|Alpha (Currency exchange data)
Information accurate to best of ability as of 26 December 2016