The actual size of the page is quite small, but bear in mind that embedded resources must be taken into account when computing page size:
The page voluntarily contains a lot of useless spaces at the end of the page to trigger a warning from the mobileOK checker about the need to use the network sparingly.
Warning: the Default Delivery Context does not support Javascript, so the size of the Javascript file is not part of the total size of the page computed by the mobileOK Checker Basic!