It's interesting to see how PV44 can appear to be cryptic to some.
The concept is pretty simple though : 4 trigger inputs select between 4 sets (columns) of 4 voltages defined by the knobs/switches. If 2 or more inputs are triggered simultaneously, it will prioritize (4>3>2>1) which set of voltages is sent to the outputs.
It was primarily developed to be used with drum/percussion synthesizers so that multiple parameters could be modified at once, and this is why it responds to triggers, have prioritization, and includes an output which is an OR of the 4 trigger inputs.
It can be used in other contexts, yet it might not be for anyone, as it's more of a companion to a trigger sequencer.