The Tudors means the people of that royal family, taken together — the five monarchs and their relatives. Because it names a specific known group, it nearly always takes the: the Tudors ruled England for over a hundred years. You will also see it used loosely to mean the whole period and the people alive in it, the way we say the Victorians. "How did the Tudors eat?" is not asking about the royal family's dinners; it is asking about ordinary life in the 1500s. That stretched use is very common in museums, school worksheets, and TV programmes. Note the plural form is doing real work here. Tudor alone is the adjective (Tudor England); Tudors is the noun for the people (the Tudors came to power). British children learn about "the Tudors" as a school topic almost the way they learn about "the Romans", so the word carries a slight primary-school flavour for many adults — friendly, familiar, not scholarly. Historians writing seriously are more likely to say "the Tudor dynasty" or "the Tudor monarchs".