We can use 'so... that...' and 'such... that...' to show that there is a certain result. (We can't use 'very' or 'really' in this way.)
It was so cold that the pond froze (= because it was very cold, the pond froze).
She felt so tired that she fell asleep on the train (= because she was very tired, she fell asleep on the train).
It was such an expensive meal that he didn't spend any money for the rest of the month (= because it was a very expensive meal, he didn't spend any money for the rest of the month).
They have such a lot of books that they need to store some of them in the garage (= because they have really a lot of books, they need to store some of them in the garage).