This file is a resource file for a spell using effect 214 (select spell). When the main spell is cast, this file is used to present several further spell options.
The first column contains identifiers for the spell names.
The second column contains the filename of each spell.
The third column is unknown.

In BG2EE we have (spwi417):
2DA V1.0
              ResRef  Type
Mace          SpWi488 3
Axe           SpWi487 3
Short_Sword   SpWi486 3
Long_Sword    SpWi485 3