New for Office 365 customers, one single formula sitting in one single cell can return many results. Those extra results will spill into adjacent cells. This is a major change to the calculation engine in Excel. Excel no longer requires you to enter array formulas with CTRL+SHIFT+ENTER and formulas that return multiple results will now automatically ‘spill’ into the cells below and or to the right.
Oz will take you on a journey of Dynamic Arrays an explore: