For testing purposes I tried the thing you did with the file path. It doesn´t work with me. Thats the new CSV (the last line is like it was before, the Fireball-line like you suggested.).
Name,Spellname,Spellicon,StrScal,IntScal,DexScal
Fireball,Fireball,“Texture2D’/Game/Abilities/Icon/Fireball.Fireball’”,0,0.25,0
Spark,Spark,“”“Texture2D’/Game/Abilities/Icon/Spark.Spark’”“”,0,0,0
After reimporting the resulting DataTable in the Editor looks like this:
http://puu.sh/f5RHV/77f0e70a02.png
Maybe I did something wrong in there?
Note: IIRC i didn´t type the link in there, I got it by rightclicking on the Icon in the editor and then “Copy Reference to clipboard” or smth like that