What are the mandarin words for these Chinese altars?
Generally, you can call all of them as 神位 which means place of god.

If you are referring to the facilities offering the places,


  
  Altar that hanging on wall (I suppose this is altar for sky god): 
  


龛 as @user3306356 mentioned, means small box used as altar. you describe them as  神龛，佛龛 ..


  2.Earth deity altar (usually put on ground level):


personally , 龛 is also suitable for this , thought they are of different size.


  3.Table altar:


供桌 a table for offering sacrifices.