SOLVED!! (kind of)

In case anyone with the same problem stumbles on to this thread, I thought I'd at least share that I found one work around (to getting downloaded lessons to play on my son's Samsung tablet). Steps below that worked for me:

1) Download lesson using desktop pc to a memory stick

2) Copy lesson from memory stick to tablet. (See below)

3) Play lesson on tablet without needing internet. Wow-that was easy!

*When copying from my memory stick to the tablet, I was given a choice to convert from Mp4 to Wav file. I chose the recommended conversion and it took a while to convert just one lesson. Not going to work if you have a bunch of lessons you are moving. For the next lesson, I just copied it over and it turns out, the Samsung tablet I have (cheap) plays MP4. The remaining lessons were copied and pasted quickly and now my son is able to watch his lessons wherever he wants and on his tablet.

Hope this can help someone