Clarification on Art-Net parameter for DMX Out CHOPs

Hi,
There are a few fields in the DMX Out CHOP that I do not understand and find the documentation a little thin.

The first is “Format”. I am not sure of the difference between packet per sample and packet per channel? Because there is just one sample per channel what is the difference?

Additionally, if I change the default value to “Packet Per Channel” I see that I can use the Art-Net routing table field.

The wiki for this says “Use a Table DAT to route channels to the appropriate DMX outputs” - can anybody clarify what exactly this means?

Thanks