These instructions are confusing ... but I cobbled them together.
1) You delete apps on the iOS device itself by pressing/holding any icon until you get the X's ... you can only delete them one-by-one.
2) You delete apps on iTunes, multiple at a time if you like by:
• clicking the 'Apps' icon ... after the Music, Movies, and TV Shows icons. (Apps is also listed in the three-dots 'more' icon, the next one to the right.)
• selecting apps...multiple by pressing the Command key, and then Control-click (or right-click) to display a 'contextual menu' with Delete.
*You cannot delete apps in the list view displayed when you click the iPhone/iPad icon when the device is plugged in ... you can delete them from the device itself. To delete from iTunes you click the three dots and go from there.