Just as before, add columns: Year, Month, Day, WD, UnitPrice, LastPrice.
Inside a Table, right-clicking gives you slightly different options. Under Insert, you'll see "Table Columns to the Right" — click that to add one column. Repeat for each column. (Selecting multiple columns and inserting all at once is grayed out — add them one by one.)
If any column headers above shifted out of place, use Cut and Paste to move them back. Then type in the column headers.
Formulas inside Tables work a lit