Microsoft just released a major stability improvement for Excel 2013. Please read this post here for details. If you have Office 365 you can get this update by clicking on File->Account->Update Options->Update Now. However, many enterprise customers still chose not to deploy Click-To-Run version of office, in which case, there are links to four Knowledge Base (KB) articles at the bottom of the article that provide manual update option.
Microsoft Releases Excel 2013 BI Stability improvements
