All his tall talk came to nothing. Here, "tall talk' means 

In the sentence "All his tall talk came to nothing," the phrase "tall talk" means speaking in an exaggerated way, where someone is making unrealistic claims or promises. The correct answer to the question "Here, 'tall talk' means..." is an "exaggerated statement." This means that the speaker was saying things that were not true or were unlikely to happen, and therefore their words didn't lead to any actual results.