Download mod_tablemakerforcsv[x].zip file and install it in Joomla. If you download release file, you should extract it to find mod_tablemakerforcsv[x].zip ...
The 'file' is empty, because - most likely - fetching the URL didn't work. Fetching URLs via the URL class is a bit brittle. Usually in all but the most trivial cases something like Apache HttpClient ...