These are backwards. The jog arrows should be the tool movement, not the table movement.When I press the "Left Arrow" button, the table goes in the Left or -X direction. I think this is also correct as Mach3 zeros the X axis.
When I press the "Up Arrow" button, the table goes in the +Y direction (into the Head). I think this is correct as Mach3 zeros the Y axis.
Left Arrow would be the tool moving left, with the X axis DRO counting down. (Table moving Right)
Up Arrow would be the tool moving back, with the Y axis DRO counting up. (Table moving towards you.)