Techradar posted a story that Office 2013 on Windows RT will be scaled down compared to the desktop version

While Microsoft has promoted the fact that Surface tablets running Windows RT will come pre-loaded with Office 2013, it won't be quite the same version desktop owners are using.Office 2013 on Windows RT will be scaled down compared to the desktop version, The Verge is reporting.According to sources familiar with Microsoft's plans, the Windows RT Office will drop support of macros, third-party add-ins, and support for Virtual Basic for Applications (VBA). There are also expected to be a small number of other missing features, though there is no confirmation on what those features might be.

  Windows RT to run a scaled back Office 2013