I've heard of that. But why is that? Is it because the French society strongly encourages immigrants to assimilate. Do Asian men blend well with French society? Is it because the French themselves aren't that tall? Are the combination of these the reasons? or is there something else?
While height is cited as a factor in attraction for women, they are not animals (to say the least). As human beings, attraction weighs in far more other things than a physical size. And the degree to which assimilation is encouraged is probably not a factor either, because we see likewise degrees of forced assimilation in other western countries (ie: Germany) yet there is no similar widespread attraction of the White female to the Asian male.
I think the actual reasons are multiple and complex. Of course even sociologists and other learned persons can give their reasons, but nobody will ever know for sure, and at best they will be educated guesses (sometime even misguided educated guesses). Here's my stab at it: France has had a long history within Indo-China. In modern times, that area has been made famous in popular culture through romanticized images as portrayed by films such as Emanuelle (in the 70's and 80's), and more recently films such as "The Lover" and "Fruits of Passion". The european French today, while being probably one of the most advanced societies in all the world, still at times harken back to the days of imperialism in a nostalgic sense when they had power and the freedom to impose one's will though today it is being reflected without the sinister reality of history. As well, modern France has the history of white male dominance and also the dominance of another male majority: the high influx of Arabian immigrants, of which the male population is seen to be about as chauvinistic as the white males of a generation past. Asian males, on the other hand, have tended to be seen as less chauvinistic (although their societies are more or less equally patriarchial) in comparison, which is attractive to the modern French female. They have also tended to be more successful as immigrants as compared to their Arabic and Black counterparts, especially in regard to education and earning power. These lead to upward class mobility, while Arabic and Black counterparts have had a harder time in that sense, and White French males are often stuck in the social roles and prejudices of old Europe thus preventing upward mobility. Thus success and affluence become traits attached to the Asian immigrant, and as we all know, success and affluence are always attractive to females no matter what country they are from. So what we have is the interplay of a positive historical background, positive economic bias, positive class mobility, and more equal treatment of the female (in comparison to other men). These factors combined help explain the popularity of Asian men to the French woman.
It is interesting to note that, however, the Quebecois woman has no taste for the Asian male as compared to her French counterpart. But from my understanding of the Quebecois, they are more like the old French and have about as much exposure to Asian males as the women from Eastern Europe. I illustrate this to show that just because they speak the same language and share much of the same culture, the dynamics that lead to attraction are so different that there can be no attraction at all.