You get a few things from logging into the Periodic Table of Office 365.
Personalized view of the Table
Once logged in, the Table grays out the apps you're not licensed for. While it's helpful to filter the Table using the licensing provided by Microsoft, it's pretty common for organizations to disable other apps or services by removing the license from users. For example, you might be on Enterprise E3 but not have access to Yammer because your administrator has removed your license. This view will show you that.
Why would your administrator remove that license? There are many potential reasons. The most common one is they're not quite ready to support this application yet. If you're interested in finding out more about how to use the app or service, reach out to your Office 365 administrator.
Launch the app right from the Table
Once logged in, the Table can know the organization-specific URL of each of your apps. You can use the Table as a home base for getting you to your applications quicker than before, and perhaps quicker than if you were to use the regular Office 365 app launcher.