Hi LearningLabVIEW,
The middle For Loop isn't actually doing anything because you're trying to index an empty 2D array constant (if you run with highlight execution on, you can see it). A quick fix is to instead replace your empty 2D string array with an array of zeros (or empty strings, or anything, actually) that's the same dimension as your Data Array.
And since you're using a Build Array function, it'll end up removing all the zeroes/blank spaces from Data Array, but it will also just append the result it to the end of your "source" array...you could just delete the first three columns afterwards (again, quick fix).
I'm sure someone else will chime in a better way to do it, that's just what I noticed in the two minutes that I could take a look!