Why does a 40 MB game take up nearly 9 GB of disk space?
View attachment 2317075
Cluster size, which acts as a kind of minimum file size, can cause less extreme discrepancies like this. If you have a thousand 1 KB files on a standard NTFS (Windows) drive, well, the default cluster size of the NTFS file system is 4 KB, so that "Size on disk" would report 4000 KB and not 1000 KB, because that's what it would actually take up. But the difference here seems to be too extreme for it to be explained that way, so I'm not entirely sure.
(e): Looks like it probably is this, as wildfire42 said and which I did not read before posting this - strange that your drive would be formatted to be an insane 1 MB, though.