The easy one is by using the plus button on the right hand side of your profile picture that is going to this URL: https://new.mendix.com/link/overview/
Then on the right hand side you see App from spreadsheet. Use that one and just upload your Excel.
You can use the excel importer module from the app store. Its rather easy to setup. Once setup you just add a new template, assign it the entity you’re importing the data to. Then add a new import file and select the template you created.