Thanks to everyone for the contributions and suggestions. When I was starting this thread I didn'r suspect that it would cause such a heated discussion. I've read all of your comments and I see now that the question raised is even more difficult than I expected before. To sum up, I can say as follows:
1) Before I decided to post my question here I consulted several natives who were my tourists and who had a very good level of education. One of them chose "Minor Dutch masters" and the other one "Miniature Dutch masters". I explained to them what the intended meaning was, but they assured me that their choice was correct.
2) The expression "Dutch miniaturist" is very clear and probably best conveys the idea of creating small paintings for private houses in Holland. Nonetheless I was wondering whether there is an adjective that can be used to describe this vast family of masters.
3) I think I agree that "Little Dutch masters" means that some artists from Holland weren't as famous and talented as Rembrandt and some others whose talent was also widely recognised. However I'm not very well familiar with the usage of the word "Lesser" and therefore here I have to trust native speakers who say that "lesser" has nothing to do with the size of a painting.
4) We should remember that even natives' replies can vary depending on a place they're from. For example, the words "miniature" and "minor" were suggested by Australians. Probably to them they sound OK in the context. However Britih people and Americans might think differently because of the existing differences between the languages. That's why it's important that people from all regions leave their comments.
5) We've questioned the existence of the word asked about at all. Well, I'm sure the word should exist since otherwise I don't think the word would be used in Russian. Probably it's not used too often, but it should be evident for experts on Dutch art.
6) What made me start searching for an appropriate word was the fact that the word is widely used in Russian. By the way, in my language we literally say "Small Dutch masters". Of course those who know nothing about Dutch art might think I mean the height of the people, but people who understand everything will realize what exactly I mean.
All the best
Bennvis, you appear not to be reading what others have written. There are two completely separate issues here:
1. The word for artists who paint small pictures - miniaturists. Those who come from the Netherlands are Dutch miniaturists.
2. An expression for minor Dutch artists, those who are not in the same league as Hals, Rembrandt, and Vermeer. Some people apparently refer to them as lesser Dutch artists, lesser Dutchmen, others as little Dutchmen.
Do you? Milan wrote in the first post,
"Probably you've heard about a very famous family of Dutch artists who lived in Holland in the medieval times and created SMALL paintings, which were intended for private houses where there wasn't enough room for big works. In the Hermitage museum in my city there are a great many works by these masters and some of them were Rembrandt's contemporaries.
I'm not sure whether or not there is a specific word in English used to describe these painters. "
We have not established whether there is a word/expression for this particular family. We have established that we can refer to them as Dutch miniaturists. Unless they are Hals, Rembrandt, and Vermeer, we can presumably also include them with the other Little/Lesser Dutchmen/Dutch Artists.
The word Little/Lesser has nothing whatsoever to do with the size of the works any of these artists painted.