Perhaps we weren't clear enough in our explanation, so please allow me to clarify on this point specifically.
As Camate mentioned first "there is a limit for the number of words and phrases that can be added to the auto-translate dictionary" - this is how the system currently exists and there is a limit to how many terms can be added to the dictionary. He then goes on to state "and adding all of these attacks would consume quite a bit of space" - "space" here refers to the number of slots that are available to use in the dictionary, a currently finite number. Hopefully that answers your question!