Microsoft Excel's Data Validation tool lets you add a drop-down list to a cell based on existing data in a column. However, how this works depends on whether the source data is part of a formatted ...

Excel’s BYCOL() and BYROW() functions evaluate data across columns and rows, returning an array result set allowing you to bypass a lot of work.

You can add a column in Excel by right-clicking or using the “Insert” option. These features are helpful for adding new data to a spreadsheet.