this is a grey area….
Volunteering could be work experience or extra curricular. I tend to advise putting it in to the section you feel needs more details/variety if you are unsure - it really won’t matter which one you choose, I would just stick to one and make sure it is not repeated.
Open days can be in employment, but if they are then I expect the entry description to be fairly brief and to focus more on what you learned from the event rather than what you did, and keep it to 2-3 sentences maximum (you don’t need to describe something that was a few hours in more than this). Alternatively, you can put them into other sections of your application.
Sometimes they fit nicely into a “is there are further information you want to provide” type questions or sections of the application. Sometimes firms will ask specific questions about the of events you have attended and so if there if a dedicated section or question like this, then I wouldn’t put them into the work experience section, I would just detail them in the specific question asking for this information.
