The women were rude demanding that the OP move, but what has moved me to respond on this thread is the weird, weird statements from more than one poster along the lines of
'these silly people who queue for food and drinks when all the tables are taken, what are they thinking of?'
Because it doesn't work like that.
I would go into our M&S cafe with DD when she was still in her pushchair, so I couldn't and wouldn't dream of leaving her at a table to 'save' a space.
As I went in, I would suss out the available seating. Generally there would be several tables available.
However, as the queue lengthened, people who had come in behind me in groups would go and plonk some of their party in the once-available tables, so by the time I'd passed through the byzantine ordering system and got to the till with DD, there were no tables free because they all had a hogger sitting at them.
So what do you do then? Is that my silly fault, for daring to venture out with a child and want to eat whilst out? Should I have heaved a sigh at my own irresponsibility and abandoned my lunch/coffee?
What I tended to do (whilst raging inwardly at their selfishness) was ask politely if I could sit at a table for four with one person (with no food/drinks) there. If they said no because they were saving it for others, I would, if feeling up to it, point out that there was a sign asking customers to get their food before finding a seat. Other times, if someone had been mad enough to leave bags there to 'claim' a table, I would move them. If they tried to argue the toss with me I would again point to the sign. I obviously look more scary than I think I do, because most people accepted I was in the right!
However, OP, I don't think in your particular case, you were in the wrong. There's no excuse for rudeness.