Import data from spreadsheet

In simulation, there is an option under the right click menu to export variables in the Execution View.  Is it is possible to import variables from a spreadsheet?

No.  There are quite a few dialogs and navigators where the user can right click and export the contents to a spreadsheet or browser. This is fairly standard NX functionality. The purpose is to get a report or do analysis of the information, so there is no provision to use the process the other direction and push data from a spreadsheet into NX.