I think there is a setting in Calibre that allows you to have the name of the book pop up instead of the filenames. I think it is associated with the epub/kindle files though. With plain text it's likely you might have to go through and individually change the metadata information. Of course you could convert the text files to epub easily enough in Calibre as well. There are a lot of books though which makes the epub/kindle format books easier to work with.
