column identifier versus separate table with related data with different purposes
In my opinion, It is very much depends on the details.


Does cleaner robot has different attributes compare to killer robot? 
Do you have different type of killer/cleaner robots?


if your answer to any of these questions is yes, Then probably you need a separate table for each type (Normalization). Using different table for different type simplifies your job when you want to extend your application. Attributes with functional dependency (2nd Normal Form) and transitive dependency (3th Normal Form) need to be placed in the same table. You may read more about pros and cons of normalization.