When you go to Tools – Import / Export Settings – Export (or Import when you have a .vssettings file that contains this category), and you look at the description for the General Settings – Start Page Commands settings category, it says, “Startup behavior… and settings for the Start Page.” This is a bug, since this description is exactly the same as the Options – Environment – Startup description.
What this category should really say is, “Represents the commands that appear on the Start Page.” For example, on the Start Page, if you go to the Getting Started section, you’ll see a list of commands. What commands appear here comes from this category.
Sorry, you can’t create your own commands here. I’ve asked and I got lost pretty quickly on what the steps might include.