Test Studio will record Keyboard actions. As it happens, however, CTRL clicks on their own will not be recorded. Instead what you can do is record a CTRL + Something click and then modify it to be just a CTRL click like this:
Test Studio will also record CTRL + Click steps. It records them as separate steps which seems bad but multiselection actually still works. You might have to set these clicks steps to SimulateRealClick=true however:
Alternatively you can do this through code:
Let me know if you have additional questions on this.
the Telerik team