If you have multiple cells selected, you can paste a value from the paste buffer into the cell, and it will be copied into all selected cells. The somewhat tricky part, is to place the value to change to into the paste buffer before selecting all of the cells to change.
Here is a simple example, and the way that I use this feature.
Using the Big Class sample data table, I will show how to change all of the column "sex" values of "F" to "Female"
The data table
The first thing is to place the word "Female" into the paste buffer, so choose one of the cells that is to be changed, and type in "Female"
Then right click on the changed cell to select it, and select "Copy" to move it into the paste buffer
Then right click on one of the remain unchanged cells and select "Select Matching Cells"
Which selects all of the unchanged cells that you want to change and select "Paste". The cells will all be changed at once
There is also a more generic Find/<Replace | Replace All> tool available.
Edit=>Search=>Find
will open the dialog box for this feature. If the element it is Finding is specific enough to select only the cells to change, then one can make quick multiple cell changes.
Using the same general selection method from above, Right click on one of the M cells for the Sex column and select "Select Matching Cells". It will select all of the M cells.
Open the Find/Replace dialog box
Edit=>Search=>Find
Fill in the Find and the Replace value, and click on the checkboxes to restrict to only the selected columns and rows,
and then click on Replace All, and all of the cell values with M will be changed
Jim