Moving files

I hooked up my tablet to the PC today with the USB cable. I mounted the internal memory of the tablet when prompted and I could see the tablet as a USB device on my computer. I created a directory on the tablet called Dave and copied some jpg, mp3 and html files to the tablet. After ejecting the tablet as a USB device, I disconnected the USB cable. Using the Gallery app I could see my jpg files; the Dave directory also showed up in the Gallery app window. Using the Music app, my Dave directory showed up as an album with my music files inside it; the mp3 files played fine.
My html files are not visible with the 2 file managers that I have downloaded: Advanced File Manager and AndroFile. I either don't know how to use them, or they are junk. I am going to try to download ES File Explorer or ASTRO File Manager next.