Fancy taking the front cover off!? If its coax cable then for sure we know it not the wiring for the phone and network connections but the TV distribution amp. The other option is to turn the left switch off and see if you loose tv signal. This is assuming you use the tv aerial distribution panel as feature in you first pictures or in other parts of your house.
Can you see where the right on/off switch goes to?
That looks like some sort of power distribution system. A network or ethernet switch would look like the link below. To be honest I would expect the previous occupant would have taken it wirh them. But .... any other cupboards? The network/ethernet sockets would be there as well.