Is there a keyboard shortcut to open a new Konsole tab?

Works for me (in Kubuntu):

System Settings -> Shortcuts and Gestures -> Custom Shortcuts -> right-click -> New -> Global Shortcut -> Command/URL -> type a name (i.e. "Terminal" or "Konsole") -> choose tab "Trigger" -> click on None -> press Ctrl+Shift+T -> choose tab "Action" -> enter "konsole" for Command/URL -> apply

By default this combination (Ctrl + Shift + T) works in Ubuntu, but not in Kubuntu.

In Plasma, the shorcut is disabled by default in example custom shorcuts:

Have to create a custom global shortcut from the system settings for the kubuntu.