Yes, I mean 'You're completely right' by 'You're quite right'.
The word 'quite' has two meanings: with 'gradable' words, it means 'fairly', 'rather' or 'very'; with 'non-gradable' words, it means 'completely' or 'absolutely'.
In other words, you can use 'quite' to emphasize that something is completely the case. You can say 'I'm quite sure', 'It's quite impossible', or 'That's quite amazing'.
So, if I say 'I quite agree with you', I mean 'I agree with you completely', but you may not be that happ