To select multiple objects in the Object Manager, hold down the CTRL key and click on each object.
To select multiple contiguous objects (all in a row) in the Object Manager, select the first object, and then hold down the SHIFT key and click on the last object. Note that multiple objects can only be selected from one pane groups (i.e. you cannot select a log item and a header item at the same time).
Updated: October 4, 2016