For some reason, my laptop’s Synaptics touchpad settings dialog doesn’t include two-finger tap to bring up a context menu (mimicking the right-click).

Having to position the mouse and physically right-click is error-prone and slower. Likewise with the included feature to two-finger click (in fact, that’s worse). It turns out the touchpad is capable of double-tap. You just have to go to the registry.

Here are the steps, mostly copied.

http://www.tomshardware.com/answers/id-1851375/finger-tap-click-windows.html

https://forums.lenovo.com/t5/Idea-Windows-based-Tablets-and/2-Finger-Tap-right-click-not-working-Win-8-0/td-p/1324087

1. To re-enable two finger tap, press Windows key + R, enter "regedit" then press enter, and on the left pane browse to the following locations:
HKEY_CURRENT_USER\Software\Synaptics\SynTP\TouchPadPS2

AND 

HKEY_CURRENT_USER\Software\Synaptics\SynTP\TouchPadSMB2c
(the first location didn't work for me, but the second location did)

2. In the right pane, double click on 2FingerTapAction and change the value to a "2" (Hexadecimal) for right click, or a "4" (Hexadecimal) for middle click. 

3. Double click on 2FingerTapPluginID and clear any value it may have.

4. In the right pane, find the MultiFingerTapFlags key and change it from a 2 to a 3.

4b. Additionally, if you want to enable three finger tap for middle click, double click on 3FingerTapAction and change the value to a "4", also clear any value for 3FingerTapPluginID and set 3FingerTapPluginActionID to "0".

5. Restart your PC and you can see the changes well enough.

Note that if you change any setting using the Synaptic dialog, the above will get unset and you’ll have to manually do it again.