Hi,

For this requirement you need to extend the length to get the default values in multi lines.

Open the UI parameter which you need default value and right click on the filed and configure dictionary.

Change the Max length to 300. Then you can set the values on 2 lines as per the requirement.

If the length of the field  is default as max length 80  then you can not give values on next lines.

Refer below Screenshots: 

Hope it helps!!

Please Mark ✅ Correct, Thanks!! 

Regards

Pavankumar