When you have an object with a material you need to apply to multiple other objects, linking materials is an easy way to apply them with just a few clicks. Here’s how.
In order to link materials in Blender 2.8 you need to select the objects you want to apply a material to first.
Holding down shift allows you to LMB-select multiple objects.
When you’re done selecting objects without a material, select the object with the already applied material last.
Then click CTRL-L and select Make Links- Materials.
Congratulations, you now have the same material linked and applied to multiple objects.