Flexmonster performance issue with attached json file

Dear supports, 
There are 3 questions we want to know more about in detail and all using the same data as the question asking by attached data files:

1. What is the different between loading a .csv data and .json data? As we tested that the same data set but different file format has a big different, for example .json has a significant increased in the number of memory (will cause out of memory in Chrome) and .csv has no problem to show all data in flexmonster (btw, memory still pretty increased).
2. As just mentioned, 10000 json records cannot be opened. Please help take a look any workaround to help showing large data.
3. Using the same data file, open local report in https://www.flexmonster.com/demos/js/pivot-table/and open local report in our web project. The data loading time spent in DEMO page is few times faster than in our project. Any ideas why is the different?

   Thanks for your team's help!

Cheers