It’s an exciting new feature included with Dynamics 365. Excel provides powerful ways to analyze and present your Dynamics 365 data. With Excel templates, you can easily create and share your customized analysis with others in your organization.
First need to create excel template using create template wizard. This wizard is also used to create excels so you can see both options are available in popup.

There are two different paths you can follow to create an Excel template:

• From the Settings page. Go to Settings > Templates > Document Templates > New (). You must have sufficient permissions to access to the Settings page, such as System Administrator or System Customizer.

• From a list of records. For example, go to Sales > Opportunities > My Open Opportunities. On the menu bar, click Excel Templates > Create Excel Template.

Once a pop-up window titled Create Template from CRM Data opens, choose the following options:

• Select a template to create: Excel Template.
• Filter by entity: Activity.
• Used saved view: My Activities.
• You can also click on Edit Columns, if you want to add, remove, reorder, or change the properties of the columns to be exported to Excel.
• Click on the Download File button.

Upload the Excel template into Dynamics 365:

• In Dynamics 365, go to Settings > Templates > Document Templates or select to upload template in CRM like before instead of selecting select entity you can use upload button.
• Click Upload Template.
• Drag the Excel file into the dialog box or browse to find and upload the file.
• Click Upload.