This was an interesting SolidWorks support question we had recently. The title of the part did not fit in the linked title block.
If you Edit Text in Window, you can see the linked text is $PRPSHEET:"Description". There is no place to add a carriage return. Is it possible to add a carriage return to custom property values in SolidWorks? I did find open SolidWorks Software Performance Report #118564: Support for non-printing characters (carriage return) when entering text into a file property. The workaround is to open the text document below.
Select all (Ctrl + A) and copy (Ctrl + C) to copy the carriage return symbol.
Then, open the custom property in the part file and paste (Ctrl + V) the character into the text string of your custom property value where you want the new line to start. Note: It won’t look like anything happened when you paste until you click OK. So, only paste once and click OK.
Neil Bucalo, CSWP
Certified SolidWorks Support Technician 2013
Computer Aided Technology, Inc.