This should have been a sort of hardware remote desktop and/or multimedia for schools.
The big db25 connector had a cable that splits into two dc15 connectors, that would go to the prev and next PC. There is a bypass to the pc's VGA card (ext. loop cable from vga card to this card, vga exit on a idc - patch not included in photo). There are also audio connections on idc that go to a patch jacks not visible in photo.
The board features a XILINX FPGA (field programmable gate array) , an ANALOG DEVICES DSP (digital signal processor) and lot of other chips.