Note the misaligned columns?
sample file:
http://apple3.org/Documents/Manuals/Apple III Owner's Guide.PDF
It displays properly in preview.
I've seen the same sort of behavior in a few other documents, like
https://www.annarchive.com/files/Drmg065.pdf
perhaps the pdf rendering method shares something in common-- perhaps I haven't been reading enough non-vintage materials to notice the tearing.
Anybody else experienced something similar? Safari version 12, macos mojave, imac 5k (2014)