I want to fill about 3000 entries in a SharePoint calendar List for testing purpose. I have tried using this link but i have some lookup columns and person/group fields which do not appear in the excel sheet? Is there any other way of adding bulk items in a calender list.
PowerShell to the rescue! You can import your data using PowerShell rather easy, including user accounts and lookups. Check out
Loading SharePoint lists from Excel using PowerShell http://davidlozzi.com/2012/02/29/loading-sharepoint-lists-from-excel/
Using PowerShell to play with SharePoint Items http://davidlozzi.com/2012/02/14/playing-with-sharepoint-data-in-powershell/
Using PowerShell to access SharePoint Sites, Users, and Groups http://davidlozzi.com/2012/03/07/using-powershell-to-access-sharepoint-sites/