'Breakfast' and 'lunch' are marketing terms designed to loosen your wallet stud. 'Tea' on the other hand is a euphemism for 'Over the yard arm'. An invitation to 'Dinner' means 'We're having a piss-up, would you like to come?'
I once received an invitation, which I accepted, to some sort of 'do' organised to recognise the contributions made by the Scots and Irish - along with a salute to the 'Little General' - to current world economics. Unfortunately the only thing that I can remember about the whole episode was waking in a hospital bed.