Hello Steve,
Unfortunately the "Show All Details" is a client side action only, and does not fire off a network request. If you hover over the link as a student you can see this by: "https://domain.com/courses/:course_id/grades#". If you notice there is a pound sign at the end. This pound sign is why it doesn't fire off a network request. This is generally referred to as an anchor link, or fragment.
I've seen two major uses for anchor links in general websites:
1. Linking to a specific part of a page (framgent/anchor). This is usually seen when you click a link, and it scrolls half way down the page.
2. Using the link style (as a stylistic choice), and then running javascript to change elements of the page or not doing anything.
In the Canvas Grades interface it uses the second option, using javascript to unhide elements, and calculate averages/etc, but that's more of an alternate point. Back to the question at hand. Anchor links, or fragments do not generate network requests as they should be either JS (which is client side (mostly)), or something already existing on the page. As such making a new network request would be inefficient, and perhaps create a bad experience (potentially).
As such you'll not be able to get that click information from the requests table.
As for the ping information this is implemented through every page in Canvas. This is when a user spends a a certain amount of time on a page. It's the clients way of making sure it's still got a good connectivity to the Canvas Server(s).
