I don’t think it’s as simple as just importing the .CSV asset into the editor. There has to be a custom-written hook up, so far as I can gather from this: https://docs.unrealengine.com/latest/INT/Programming/Gameplay/DataDriven/index.html
In a forum post (Read data from File - Some kind of dynamic level - Blueprint Visual Scripting - Unreal Engine Forums) Joe Conley writes: “The format the .csv files are in isn’t well documented yet, nor is the process of defining the type of data for the columns in a Data Table, but I’m hoping to write a blog post on it sometime in the near future. Right now this is a C++ feature, but we’re looking into making it more accessible from Blueprints and require less programming (or preferably none), but we have a fair amount of work to do in this regard.”