If you have data in one column that you’d like to split into separate columns (for example, split a column of full names into separate columns for first and last names), you can’t do that yet in Excel Online.
Instead, if you have the Excel desktop application, you can use the Open in Excel button to open the workbook and split your columns. Here’s how:
Click Open in Excel and split the contents of a cell into adjacent columns.
When you’re done and you save your workbook, it continues to be stored where you opened it in Excel Online.
To stay informed about updates to the Excel Online features, visit the Microsoft Excel blog.