Though you can manually copy and paste multiple cells, you can swiftly copy and paste the values of one or more adjacent cells using the fill handle.
To use the fill handle simply select the cell(s) that you would like to copy. The handle will appear as a small box at the right-hand corner of the selected cell(s).
Click, hold and drag the handle until all of the cells that you would like to fill are selected. You can drag horizontally or vertically as long as you are selecting cells that are adjacent to one another.
Release the mouse to fill the selected cells.
You can also use the fill handle to continue a series. The handle recognizes when a selection of cells follows a sequential format, whether it be number, day, or time. To continue a series simply select multiple cells in the series and drag the handle.
For example, dragging the "1, 2" values of two cells will extend the numeric sequence to "1, 2, 3, 4 . . .."
To extend a numeric or date sequence, first configure the column as a number or date field type.