If you want to include the rules in the module, then perhaps consider to make it into a PDF. Also, you should not compress the individual files - files will be compressed by the top archive.
The culprit seems to be the file help/Rules:Belter module.vmod which is just shy of 210MB. It does not really make sense to put a module inside another module, especially not in the manual. The next largest file is help/Rules:Belter base module.vmod which is almost 43MB, followed by a sound file at almost 25MB. You also have a lot of graphics files that take up quite a lot of space. Presumably, these are already in the module as boards, counters, tables, and what not.
It seems like your `help/Rules’ folder is mainly a dumping ground for all sorts of stuff *you even have copy of the VASSAL designers guide in there). Perhaps it would be better if you kept that out of the module proper. If you want to make it available for others, set up a web-site or something (for example at GitHub/Lab/…) where you store those things.
Yours,
Christian