Do the following:

1. Click on the data (cell) you want to place on the first line of the label.
2. Hold down the [Ctrl] key on the keyboard. While holding down the [Ctrl] key, click on the data you want to place on other lines.
3. Release the [Ctrl] key after you have selected all the data you want to place on the label.
4. Click on the P-touch Add-In icon on the toolbar .