滚动时，表格视图更新速度更快

I have a table view in my view controller, and when I hit a button, it should search for data online and fill in the table view cells. For some reason when I run the following code, it takes ~10 seconds to load the table view. But, if I hit search then slide the table view 1 second after, it loads instantly. Is there any way I can make it load instantly without having to scroll down it?I have a table view in my view controller, and