It's perfectly normal. To help oneself to something is an everyday idiom, meaning to take something (often food, but not necessarily) for one's own use, not waiting for somebody else to serve them or give permission.
The phrase the establishment in a nation (here, France) or a society or organisation, means the powerful senior people, especially those who approve of the way that society is currently set up (established):
the important and powerful people who control a country or an
organization, especially those who support the existing ...
It is not “wrong” to refer to how strongly heat is transferred, but it doesn’t fit well here. It has a different meaning that is not commonly applied to a transfer. When we describe a process we are more likely to talk about how well, how completely or how quickly the process occurs, not how strongly it occurs. We are usually discussing “degree” not ...
According to Cambridge Dictionary,
to be up to smth: to be doing something, often something bad or illegal, usually secretly.He looks very suspicious hanging around outside - I'm sure he 's up to something
Thus, in your phrases, it means the person is asking what the other person is doing (implicitly suggesting a bad connotation).
The compound modifier turn-of-the-century means "of or related to the period near the turn of the century."
So depending on context, "turn-of-the-century India" might mean something like, "India as it was during the period roughly between 1890 and 1905."
"Turn of the century" means either "about 1900" or "about 2000" (or occasionally 1800, 1700 etc).
From the context I'd guess that it means "about 1900" in this sentence.
So it means that man-eating animals were common in India and Africa in the time 1890-1910 (roughly).
The wider context for this is that much of Africa and India was under British imperial ...