Some of the Reason 3 devices have more than one page of parameters. To access the other pages repeatedly press any row-select button on the ReMOTE SL.
The Mixer 14:2 device is a special case because as well as having multiple pages of parameters it also has two groups of pages; one for channels 1-7 and one for channels 8-14. To switch between the groups use the left-hand scroll up/down buttons on the ReMOTE SL.
It is also possible to change the currently controlled Reason 3 device from the ReMOTE SL. To do this press the right-hand scroll down button and then use the buttons immediately below sliders 7 and 8 to change the target track.