But you don't have to store them in a file system (many file systems will use 8k blocks, where each block can be used by at most two files, hence the 4096 bytes you mention. But some file system can subdivide blocks into smaller fragments, and allow you to use smaller blocks as well, but I disgress) - you can store them on a raw disk as well. Using a format (such as P4) that has a fixed size, finding them on a raw disk would be easy.

Of course, even if it was feasable, there's no point in generating and storing each possible image. You might as well generate the images when you need them.

I don't know where you get your 246 bytes from

Windows Bitmap.

But you don't have to store them in a file system

I already covered and explained that. The minimum non-compressed size (i.e. no space lost to headers and disk format) for monochrome 8x8 images is 147,573,952,590 GB. Even if it's compressed down to 1% of it's original size, it would still be 1,475,739,526 GB.

there's no point in generating and storing each possible image.

We could study the time domain, which maks this venture equally unfeasable.

Even if it's compressed down to 1% of it's original size, it would sitl lbe 184,467 TB.

You are basically storing every 64 bit pattern - each pattern once, and only once. Unless you compress the entire collection (and then you can compress that with an almost 100% factor - just compress it to your generating program), you're not going to compress it.