This file set the starting xp of particular subrace, to balance subrace with ECL.
The left column is the race ID. The right column is the starting xp for that race.
In IWDII we have:

2DA V1.0
0
                VALUE
HUMAN_TIEFLING  2000
HUMAN_AASIMAR   2000
DWARF_GRAY      5000
ELF_DROW        5000
GNOME_DEEP      5000