Yes people do it all the time, you write code (whether it be C++ or Blueprint) that spawns/creates/constructs objects of classes at runtime (of the game that is). But I think you have it somehow in your head that you want to see the array already filled in the editor before you even press play.
For actors you could indeed drag them into the world and then you could select them with the dropper thing of the array and fill it like that. But UZ_TXDATA is not an actor so that’s not an option anyway. I guess you could use the construction script to create instances and fill the array that way, then you would see the entries in the editor.