Meaning of Object Cache

[Guest]

[g.vecchi]

Hi all! I'm running EFW Community 2.4.1
I'm configuring HTTP Proxy + Content Filer but I can't really understand the meaning of "object size" in Cache Management.
So, when I set Maximum object size (KB) = 1048576 I expected that downloads (files) will be cached until 10 MB and all clients can donwload them directly from proxy, without going through the internet, but it isn't.
What does EFW mean as an object?

Thanks