It is also the case in Australia, based on my experience Windows tablets are at least as common as Android ones. If it's a regional anomaly, that has to be a very wide region then :-)
Jokes apart, I have noticed that in developing countries (I regularly visit Thailand for example) Android tablets are still more common than Win 10 ones, I believe it's because in those countries many people were first exposed to computing in the form of a smartphone, so they prefer a mobile OS like Android, whereas in the western world most people (except perhaps very young people) were accustomed to use a personal computer long before they even had a smartphone.
Jokes apart, I have noticed that in developing countries (I regularly visit Thailand for example) Android tablets are still more common than Win 10 ones, I believe it's because in those countries many people were first exposed to computing in the form of a smartphone, so they prefer a mobile OS like Android, whereas in the western world most people (except perhaps very young people) were accustomed to use a personal computer long before they even had a smartphone.