Open a document with a table, then do one of the following:
Select a cell: Click the table, then click the cell once.
Select a range of adjacent cells: Click the table, click the cell once, then drag a white dot any direction across the range of adjacent cells.
If you drag the yellow dot, you copy the cell contents to the rows you drag over. If you do this accidentally, drag the yellow dot back to its original position, or press Command-Z on the keyboard to undo the action.
Select nonadjacent cells: Click the table, click the cell once, then Resize, move, or lock a table in Pages on Mac