Sadly the image is not clear to see the chips markings :(
I do not recognize the board but the central DIL40? (I think AMD) chip looks like a CPU or MCU so it might be a whole computer or its just used to lower the IC count as a addressing mode selector/configurator or whatever.
The ICs with white label are most likely EEPROMs holding either firmware for the CPU/MCU or some custom stuff for the target computer (in case its a memory card).
The other 2 DIL40? ICs on the right can be anything (from a FDC/DMA/PIO/SIO or simple multiplexers/demultiplexer or whatever else).
The connectors are for quite a few wide cables. Based on the count of connectors and the pins count it looks more like for connecting peripherials then a master computer BUS connection which implies this is not a memory card. All the memory cards I saw got a connector that fits into single BUS slot on a PCB without cables (You do not want too long BUS connections due to noise and signal degradation).
Also the Reset? button on the right nearby the Crystal suggest this is a Computer board.
The 3 pin IC with heatsink on the top should be a Voltage regulator suggesting this has its own power supply whitch also suggest whole computer board.
So my educated guess is that you're right and this is a computer motherboard.