Hi Team,
I was not able to find any documentation on how Catalog > Products > [Import from Excel] work.

Following are mu questions.

1. Is there a standard template for products import
2. If so, how Mapped Specification attributes and other attributes data to be defined in excel.

Hi,

If you export products from your store you will see a template for import. In the case of specification attributes, they are not imported. You can achieve that with Web API for example.