Difference in scale between mean page loading times and exponentially distributed page loading times?
The time to load a web application is a sum of multiple factors, including at least:


The round-trip latency to initiate a TCP connection to the server (or maybe multiple connections, depending on your application and your browser) -- also called RTT time.
The time to download all of the page and content that it causes to be downloaded.


The second factor depends on the amount of delay you're adding; the first doesn't.  Also, the multi-page application might cause more TCP connections, causing more of the first type of delay; but it downloads less data, so less of the second delay.

So there's no reason to expect things to scale as simply as you are expecting.  Instead, the resulting performance will be a more complicated function of page size, RTT time, and delay.

Heuristically, we can expect a RTT time of a few hundred milliseconds per TCP connection, though that will depend on how far the client is from the server.  You say there's an average delay of 1 second per 200 bytes downloaded, so for the single-page application, you expect 267KB / 200bytes = 1367 seconds of delay added, on average, due to your artificial delays; for the multi-page application, you expect 58KB / 200bytes = 297 seconds of delay added, on average.  Without the artificial delays, the time to download that much data might depend on the speed of your network.