It’s rare that I am writing about third party control but Telerik grid has a new feature that is kinda hard to find any way to implement. If you want to insert a new row to a Telerik ASP.Net MVC grid that you need to add a call to the method InsertRowPosition. This can be done inside the method Editable of the grid.
This is a short snippet of code to demonstrate how to add a row at the bottom of a grid with Telerik Grid.
Of course, to the button to add a new row you need to use the ToolBar method to add a command to insert. This is done by adding ToolBar method to the Telerik().Grid().