Well, it's got something to do with television or video processing. The boxes for NTSC and PaL imply that. Also, there's a bank of VRAM labeled "Frame Buffer" so presumably it can work as a video card or drive a television type monitor as well. It looks like it used to have some kind of break-out box that connected to the connector on the end of the card.

I think "Digital F/X" was the name of a company back when? You might try googleing on that term.