What is it?
The fill cells with filter can be used to append, prepend or set the text of an entire column.
How is it used?
Add Table Filter > Fill, Replace & Overwrite > Fill Cells With …
After applying the “Fill Cells With …” filter, the first two options are to add text to all cells in the column or set the text of a column. The Add text to cell option includes fields for specifying which text you would like to include and whether that should occur at the beginning or the end of your data.
A common use for this filter is when a currency amount may be missing from a column of amounts.