In my experience, there are teas and there are teas.
When the main meal is served in the middle of the day, the evening meal can be called 'tea' or 'meat tea'. This can be a fairly substantial meal with leftovers, cold cuts and, perhaps, a simple cake.
High tea, or sometimes 'cream tea' is the fussy little meal with finger sandwiches, pastries and the Palm Court music playing in the background.
High tea and cream tea are not the same thing.
In the UK, 'tea' can mean one of the following:
1) Tea, the drink.
2) Afternoon tea: sandwiches, little cakes, etc, cup of tea, eaten at 4ish
3) Cream tea: cup of tea, scones with jam and cream, possibly also sandwiches, eaten at 4ish
4) High tea: more substantial than afternoon tea, may involve pies, sausage rolls, sliced meat, as well as cakes, sandwiches etc. Rarely seen outside of children's parties and Enid Blyton novels. Served at 6ish
5) Tea. What us folk oop north call dinner (which, confusingly, is what folk oop north call lunch).