If you only want a few books from a very big archive then I suggest you drag the books you want out of the archive into a folder and then add the books to your Calibre library from that folder. Any archive utility worth its salt will allow you to drag items out of an archive into the file system.
If you have folder that Calibre monitors for new books then you could drag them out of the archive into that folder and then Calibre will automagically add them to your library and remove them from the monitored folder.
BR
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