How to Open Multiple CSV Files in One Excel Spreadsheet. The CSV file extension appears on text documents that contain comma-separated values. Like spreadsheet data, each line in a CSV file ...

Microsoft Excel has an import wizard, but if you structure the text correctly, you can bypass the wizard altogether.

If your Excel files are opening in Notepad on Windows PC, here's how you can reset the settings to make .xls, .xlsx, etc files open in Excel.