It appears that the contents of that folder are written to RAM when Safari is launched...
Bear with me...neophyte questions...Would that be why there are so may complete URLs? Are they complete so that, when these addresses are loaded into RAM, there is an immediate connection to the sites?
I note than many of the URLs don't use www after HTTP:// For example:
.a.tribalfusion.
ad.ca.doubleclick
app.quotemedia
googleads.g.doubleclick