Having out of date and unwanted templates in your configuration pack for the excel extension can be annoying and can cause mistakes.
To remove the templates you will need to go to Openground and the configuration pack, select the pack you are using. Then go to manage components, select from the drop down excel report templates.
There are two states which the sheets can be in the first is active and the second is inactive. If you don't need a sheet but don't want to delete it you can set to inactive and i will not show up as a option.
If you would like to delete a sheet you can use the delete button at bottom of the window.