First in the Orbit program go in Parameters page from the left menu
If you milled down 2mm from your table subtract 2 from Under wood table Z position and also from slab probe Z position, also if your machine has vacuum lifters also from Vacuum Z position.
Since most the values are negative mind that -100-2=-102
Open file explorer and navigate to 5axis\subroutine or cnc\subroutine open the parameters.ngc file and near line 22 find the #<_zSlabProbe>= and also subtract 2 from the value displayed on this line, and if your machine has vacuum lifters also subtract from #<_zVacuum>= value.
subtract 2 from all of these values as well
#<_CuttingTableZ>= value
#<_CuttingTableZSecondTool>= value
If you don't find these parameters, which are normally the first two, then please navigate from file explorer to C:\Pegasus Data 3\Marble\Machines\AitalMAC 5 Axis TCP\Oribt xx\ and open the Script.txt file, at the beginning of this file at about line 10 you will find lines that start with G10 L2 for all of these lines there is a Z value, subtract 2 from all of these values
for example if original lines would be
G10 L2 P3 X0 Y0 Z-423.5 (G56 normal spindle center touch table)
G10 L2 P4 X0.5 Y-1.5 Z-422.5 (G57 spindle center touch table)
G10 L2 P5 X0 Y0 Z-240 (G58 Vacuum touch table)
to subtract 2 they need become
G10 L2 P3 X0 Y0 Z-425.5 (G56 normal spindle center touch table)
G10 L2 P4 X0.5 Y-1.5 Z-424.5 (G57 spindle center touch table)
G10 L2 P5 X0 Y0 Z-242 (G58 Vacuum touch table)