In PDF-Suite you are able to change from Multiple to Single document view.
In Single each file you open will be a new instance of PDF-Suite.
In Multiple each file will open in a new tab of the same instance of PDF-Suite.
You can toggle between them by choosing the mode you’d like to use in the View Module.
You will be prompted to restart PDF-Suite so that the changed can come into effect. Click on Yes.
PDF-Suite will restart.