Blank Cards? Literally never seen this

Howdy yall, my friend and I were opening the brick for an Astral Radiance Build and Battle Stadium, and these cards were in the back of the brick. WTF?! They all looking in bad condition, and I assume we're meant to be thrown out or something, but... what do I do now LOL. Is this something collectors look for? I'm not much of an error collector myself so if yall know please imbue me with knowledge!