You can import excel using simle flow like below. 

This same flow (with one additional condition of importing data only when there is no record in entity) can be created using bootstrap data from excel option available on entity.

If you want to import data only once then you can do it using bootstrap option else you can use this same logic (you may need to do some modification) in your application to import excel at runtime.

Hi,

Created a structure for that excel attributes and defined record definition as that structure. 

then loop that structure list and insert it in entity.

Please, check this documents too:

• How to update a Bootstrap Action to fetch an entity identifier from Excel
• Excel to Record List (component)

If you want How to Export Entity Data to Excel or How to customize the export to Excel, please check this documents.

I hope this help you,

Cheers,
Nuno