By enabling web browser like tab in Microsoft Office (for Word, Excel and PowerPoint) you can quickly open multiple office documents from tabs and can also save your taskbar space.
OfficeTab is a plug-in for Microsoft Office 2010, 2007 and 2003 and it adds tabs to Word, Excel and PowerPoint applications.
OfficeTab is a fully customizable tool. You can change the color of the tabs, apply any one of the 11 included styles, place the tab-bar at top, bottom, left or right of the workspace, change tab width etc.
Moreover you can also assign keyboard shortcuts to quickly switch between opened tabs.