If the file is 300MB total for the whole season, it is either a corrupted sample or a virus.
As of my latest knowledge update, the TV series "Arrow" concluded with Season 8. There is no official Season 18 of "Arrow." This post assumes you meant a fan-ordered collection (e.g., a complete series box set) or a typo for another show. I have written the post to address this while still targeting your specific keyword phrase. arrow season 18 complete bluray 720p single link
Use or MPC-HC for the best playback experience. If the file is 300MB total for the