The wealthy matron is so proud of her valuable antique vase that she decides to have her bedroom painted the same colours as the vase .
As far as l know we should use "such that" not "so that", am I wrong?
Plus I have never seen the usage of the verb "decide" with present tense?
The sentence is correct.
Both "such that" and "so that" are used in English. But here we actually have ".. so proud..." and then later a "that" clause. This type of structure is quite common
I was so happy that I danced on the table.
I was so happy with my exam result that I danced on the table.
The verb "decide" can have its normal present tense. Here it seems to be commentary: a narrator is describing a scene as it happens, this is one of the standard uses of the simple present. Narration or commentary doesn't often happen in conversation, but it is a standard technique in fiction writing and sports reporting.
The goalkeeper kicks the ball. It lands at Messi's feet. He dribbles it forwards and shoots. It's a goal!
