This file indicates base thief skill points, and racial bonus or penalties.
The first row (titles of columns ) is filled by the names of features affecting of PC (like PICK_POCKETS for example).
The first column is filled by races identifiers.
The rest columns are filled by modifiers for given race.

In PSTEE we have:

2DA V1.0
0
             PICK_POCKETS OPEN_LOCKS   FIND_TRAPS   STEALTH
HUMAN        0            0            0            0
DWARF        0            0            0            0
ELF          0            0            0            0
GNOME        0            0            0            0
HALF_ELF     0            0            0            0
HALFLING     0            0            0            0
TIEFLING     0            0            0            0