Not a lunch buffet (that I know of) but you might be thinking of Claude's Mini-Club in Marigot that has an extensive buffet. We haven't been there but heard many good reviews over the years. As far as Tropicana, we have been going for lunch the past several years so I can't say if more people go at dinner. When we used to go for dinner it was a pretty even mix of visitors and local folks and always very busy!