First you would need to convert the dvd films to a smaller size suitable for the tablet. Amiersoft DVD ripper is one example, but most of the ones out they all do the same thing.
Aimersoft DVD Ripper: Best DVD Converter to Rip DVD Movies | OFFICIAL
Once you have ripped them to a manageble size then either transfer (copy /cut & paste) them to the sd card using the usb lead connected to the tablet or use an SD card reader.
What is OTG? I keep seeing this. Only thing I can think of is "on the go" <lol> I have one of these. Is this what you guys are talking about?
With usb otg you can also use exFat format, even with the kitkat update, its even better because you dont have the 4Gb file size limit. Also you can transfer the video files and play them without conversion, I have played 6Gb iso movies, 12 Gb mkv video with dts sound, and multiple audio tracks, I have yet to find a video format I cant play in this tablet smoothly, so far the only thing that doesnt work is 4k video which plays very choppy and is to be expected.