I am also interested in seeing a "solution". I know that for movies and TV series, I can "get" them from my Mac to our iPad by using the free application VLC Streamer. To do that, that software needs to be on both our iPad and on my Mac. In actuality, what I do is 1) connect an external SSD to my Mac Mini containing Movies and TV series on one of its partitions, 2) launch VLC Streamer on my Mac MIni, and 3) via our in home WiFi network, "copy" (stream) a Movie to the iPad. For TV series with multiple episodes, only can stream one episode at a time. Not necessarily the fastest way, but it works. Firm there, can launch VLC Streamer on the iPad, and watch the movie/TV series episodes.
Not sure if I can "stream" files via VLC Streamer.