I'm doing an activity that the terms and conditions state there is no personal accident/personal liability cover, What does this mean?

If you will be participating in an activity listed in the table of covered Sports and Activities, in the PDS, that states there is no Personal Accident/Personal Liability cover, it is just these two sections of your travel insurance that will be excluded. If you have an accident and injure yourself, you will still be covered for medical expenses, but you will not be able to claim under the separate Personal Accident or Personal Liability sections.