To add non breaking space in the visualization title follow the below steps:
1) Right click the visualization, goto Properties > General > Title.
2) Enter the text.
3) To add non breaking space, make sure NumLock on the keyboard is on and then click on Alt + 255(use the numeric keypad to enter 255, refer to the screenshot below ). Once the Alt key is released, it will add a non breaking space:
Note: For multiple spaces, use Alt + 255 multiple times
Note: For keyboards that doesn't have a 'NumLock', refer to the laptop/keyboard manufacturer's documentation on how to enable NumLock