I'm really stuck here. How can I design an in game qualitative questionnaire that populates all text into an Excel spreadsheet for further analysis later on

Search for dataTable . This is how you’d store text (using Excel). Use structures, to have this text stored. Then parse structure elements. You should do a research about dialog systems . Here is one of them: http://www.nissyokugames.com/hakabanes-ue4-tutorials/tutorial-basic-dialogue-system/