Hey @Washeteria! You should be able to do this by heading over to Settings > Data Export in Wave on a web browser, which will send you an email with a CSV file of several different items in Wave, one of which being a customer list with these details. You should then be able to import this file into excel.
I've included a guide on how to get a CSV file running in excel: https://www.hesa.ac.uk/support/user-guides/import-csv
Good news is we're working on getting an integration with Zapier and Google Sheets up and running, which when done, will be able to export these details to a spreadsheet automatically for you. If you'd like more info on using Zapier with Wave, check this out: https://zapier.com/apps/wave/integrations