I am developing a LateX package (http://www.openlilylib.org/lilyglyphs) which contains a number of small PDF files. Currently there are only a few dozens of them but as the
I know this is an old post but I found it whilst searching so other people might as well. Here are some options I found
As it has been pointed out, a lot will depend on whether these source files will change over time.
One option you have if they don't change (or change infrequently) would be to keep a copy of them on a server you control or on a Cloud storage option and make your install script download them rather than produce them.
This would probably depend on the user having wget or curl installed but most people do and if they don't, you could always prompt the user to download them manually.
If the PDFs do change with the source frequently, you could look at GIT LFS. I have never used it myself but have seen it used.