Your restrictions are an intelligent move. To try to list all robots would be daunting if not impossible.
I included some of the Game Robots because of the way the entertainment industry likes to release live action game and comic movies. Understanding that if it is not released yet there can be no entry, the references may still be valuable at later dates.
I'm not sure how close you are to publishing. Perhaps, if your first published book is a success you may find the inspiration to publish follow-ups?
As technology advances you might find that real robots are included in fictional movies & TV. Likewise we should see more complicated and accurate robotics as scientific knowledge becomes more extensive.
Here are some ideas just to get your creative mind pondering:
Appendix by decade or year
Follow-up book by robot class (weapon, servant, explorer,etc...)
Follow-up book by scientific accuracy
Follow-up book by literary reference
Section on effects crews that construct and enable robots in fiction
Behind the scenes production screenshots
Information on last known location of the actual movie prop
Factoids of examples of the robot in actual real life situations
Concept sketches of different versions of a robot
I'm not trying to tell you what to do - just suggesting things that might unlock possibilities that you may not have considered. I am sure your project is strong as it is and I look forward to your publishing announcement.
I have The Comic Book Encyclopedia
And I find it seriously entertaining and educating.
I also have Barlowe's Guide to Extraterrestrials
And Barlowe's Guide to Fantasy
All three make me want for more!
I am sure your book will grace my shelves as well.