QTableView perform bad on Windows 10

I'm using QTableView with a very simple model, added about 10w rows with 100 columns,
It need like 20+ secs to be loaded and eat up over 6000MB memory, and the selection of the rows is slow too.

It reproducible on Windows 10 20H2 and 1909,

but it also [confirm|https://forum.qt.io/topic/118086/slow-performance-and-large-memory-usage-with-qtableview-in-qt-5-15/2] that it run fast on both Windows 7 and Linux with Qt 5.15

Also I happen to get very fast performance after reboot my desktop once, but after that , reboot does not help anymore

The same code works well with Qt 5.9.9 build on both Windows 10 20H2 and 1909.

I attached the code below.