If you have many links on any web page that are required to be opened then do not worry you do not have to open all the links one by one.
There is an add-on in Firefox that does all this and which not only opens all the links at once but also copy or bookmark multiple links at the same time.
1. Make sure to install the add-on.
2. Now whenever you visit the links on the web page right click and hold to drag a box around the links.
Image source: Multi Links
3. Now it is on you to copy, open or bookmark all the links at once.
The plug-in will also give you more options to customize.
Download Multi Links