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#11
Anything Metro would be MS online store related there. They act much more like HTML files and not desktop shortcuts you can easily trace back to the registry. It's like pinning web content to the Start tile section there. The option to add simply brings up another screen presently loaded by default with options for fonts and not any apps at least on the latest Insider Preview build I have on a VM at the moment in contrast to the 10240 RTM build you are running.
When going over that list you are looking at things like the Insider hub and other demo apps like handwriting, optical character recognition, text-to-speak, typing, etc. that are the typical pinned items you see from preinstalled MS apps as well as what you put on. These are more like what is seen with the Linux Mint Debian distro with some 200 optional packages you can select to see download and install. You have to remember those are all optional features and not what comes included with the basic 10. The hub is only downloaded once you have signed up for the Windows Insider Program there.