How to export local variable data to excel

Without any plugins, you could create a CSV file using the textfromtemplate smart service.

Any reason for not using the OOTB export record list to excel? If possible, I would recommend making a record of your data and then using record's export feature. 

Or if that is not possible, here is the plugin that I use which helps me doing minimal efforts  - community.appian.com/.../export-json-to-excel