Spreadsheets are exported from your project as comma separated values
CSV files will open in spreadsheet software such as Microsoft Excel, but without fancy text formatting.
You can also upload CSV files into Google Docs.
CSV exports take the format of locales in separate columns, leading with the developer Asset ID:
|Asset ID||English, en||French, fr||Spanish, es|
|hello||Hello world||Bonjour tout le monde||Hola mundo|
|goodbye||So long!||Au revoir||Adiós|
This format can also be imported into Loco.