This file defines lore increase per level according to creature class.
The first column is filled by classes identifiers.
The second column is filled by modifiers per level for lore for given class.
In BG2 ToB we have:

2DA V1.0
1
                        RATE
MAGE                    3
FIGHTER                 1
CLERIC                  1
THIEF                   3
BARD                    10
PALADIN                 1
DRUID                   1
RANGER                  1