In fact, you can find the server stats from back then: http://web.archive.org/web/19970822145424/http://www.bath.ac...
This says that it transferred "3 599 Mbytes" and there were "728 506" requests. Interpreting "3 599" as 3.599 gives 4.94 bytes per request, which is absurd. It must be 3.6 GB, making each response just under 5 kB. This seems much more reasonable.
So the number on that page should probably be interpreted as 63 GB, which is reasonable if we assume the site became more popular later in the year, as the original source suggests (3.6 GB*12 = 43.2 GB, and the stats are from May).
Also notice the following year (1998) says 126 MBytes and in 1999, 197 GB. That's an order of magnitude jump!