This is the 17341st most frequent Russian word.
таков
"Such is" or "so is."
The word 'таков' here describes the state or nature of the subject 'выбор' (choice), emphasizing the definitiveness of the choice.
Таков был мой выбор.
Such was my choice.
The word 'таков' in this sentence introduces a comparison or alignment with expectations ('каким я его представлял').
Он был таков, каким я его представлял.
He was as I imagined him.
The word 'таков' underscores the inherent and unchangeable quality of the 'закон природы' (law of nature).