huh, found it interesting that a search of "Tab size, tab length" didn't produce anything in here.

so, after hunting around and finding what i was after, i thought i'd share with others performing a similar search in the future.

Tab size (length) in text is a setting within the text family itself. it seems the default is 1/2", and if you want to change it to anything else, you are allowed to change it under the text's Type Properites dialog.