Yes it should have said what I had found espeically as I started the thread askingfor help, thank you David for jolting me, and yes I think I preferred the set surcharge. This is what I found when clicing on Details.
A £10 per person reservation charge is required to secure your reservation. For Sindhu bookings made via My P&O Cruises, a 20% discount will be applied to all food items, and the prepaid reservation charge deducted from your bill.