This file is not used by the engine - it is left over from BG1. The starting abilities filenames (SPIN101 throuugh SPIN106) are coded into the executable and are assigned on a probability scale based on character alignment.

In BG2EE we have:

2DA V1.0
SPIN103
        1         2         3         4         5         6
L_G     SPIN101   SPIN101   SPIN102   SPIN102   SPIN103   SPIN103
N_G     SPIN101   SPIN101   SPIN102   SPIN102   SPIN103   SPIN103
C_G     SPIN101   SPIN101   SPIN102   SPIN102   SPIN103   SPIN103
L_N     SPIN101   SPIN104   SPIN102   SPIN105   SPIN103   SPIN106
N_N     SPIN101   SPIN101   SPIN105   SPIN105   SPIN103   SPIN103
C_N     SPIN104   SPIN104   SPIN102   SPIN102   SPIN106   SPIN106
L_E     SPIN104   SPIN104   SPIN105   SPIN105   SPIN106   SPIN106
N_E     SPIN104   SPIN104   SPIN105   SPIN105   SPIN106   SPIN106
C_E     SPIN104   SPIN104   SPIN105   SPIN105   SPIN106   SPIN106