Can I click on multiple categories at once on SafetyWallet dashboard

Yes, you can. If you really want to, you can click on all the categories! But this is not very helpful though because it just opens all the filters and reveals all of your findings in the Guidelines Section.

The purpose of clicking on a category is to determine all of the findings you have of a particular type and how they can improve your compliance so you can then focus on fixing these before moving onto another category. These findings are then displayed in the Guidelines Section so that you determine your best course of action for improving your health and safety compliance.