Hi, although we are working on a new Library Browser, it's yet on a very initial state and there is not a beta available.
Anyway, i doubt we could implement a way to automatize the library creation for multiple Max files, because it's necessary to define the object to import from each scene.
In this case, i would suggest you edit the catalog index manually (index.xml). It's a text file on XML format, which is very intuitive to understand.
Of course you need to define the <maxfile> and <object> values manually, but that will be much more faster that import each scene with the Browser.
Edited: sorry, i completelty forgot that the current library allows to import from multiple Max files, but with some limitations. More details in the below posts.