set table view section number to 2, and set each section row to 3
implement the method tableView:cellForRowAtIndexPath:

create cell with default style, and configure the cell text with 'Hello World'
set window rootViewController to MainTableViewController

we can see 6 (2*3) "Hello World" row on the screen now
change .xib table view controller style from 'Plain' to 'Grouped'

1. select MainTableViewController.xib
2. select 'Table View'
3. show the attributes inspector
4. Table View > Style > 'Grouped'