If you want to edit the Let's Play Minecraft page, you need to do something different. As you can see from the page, there are tabs. You cannot edit directly from the tab, but you can do it by doing this: In the search bar, type PageName/TabName. It will take you to the page where you can edit the page's content and the tab should update to the edit.
To add tabs, create new pages in the style of PageName/SectionName (You can technically create your own page, but it's easier to search if you do it this way) You MUST create a new page, otherwise the tab won't be able to work. then add all the information to that table. Note that this will be easier to do in "Source" mode when editing, just see the top right corner of the editing window to switch between visual and source. Then make the tabs like:
...(so on an so forth for the tabs you want to add)
If you do it right, you should get something like (using the LP Minecraft scoring and Versus statistics as a guide)