I never heard of Blyton neither, wonder how she made the list.
I don't think that the number of translations necessarily means that there are a lot of people reading them. We would have to have the top 10 bestsellers (hopefully when people buy the books, they read them
) of all time.
However, quantity (how many people read) does not necessarily mean quality, even if quality may be subjective (what is "good" for you may not be so good for someone else). But surely, in the long run, books that stood the test of time would be the favorites of most people and well read (and reprinted) - quantity and quality wise.
I have not been able to find an official list of the top 10 translated books anywhere yet. I must say that I was surprised to see "The Way" of Lao Tzu as number 2, I thought it would be more the books on Greek philosophy that would make the list, since it is a well known fact that Greece (Greek ideas) is the cradle of Western civilization. But that may be the reason, Western, so maybe the Greek books have not been so much translated into non-Western languages, I don't know. It would be interesting to find the official top 10, because it may be an indication of ... what?? That is the question.