This was submitted before, but I think it really deserves some attention. Dylan gives a boatload of context to how and why UTF-8 came along, and how/why he learned about it. Watch this, and you'll understand so much more about text encodings.
If you over-analyze things, there's no such thing as "a table", also (it's all molecules in a quantum fog pattern").
But there absolutely is something that can be called plain text for all intents and purposes.
There were thousands years of plain text. And then computers have appeared.