An amused, surprised narration. ~おうと (volitional+quotative) marks the purpose/intent behind an action — 'with the intent of X-ing.' ~たら conditional for 'when/if.' どかどか is a mimetic for multiple heavy objects dropping or clattering. ~本 is the counter for long cylindrical objects like cans, bottles, sticks. も after a number emphasizes surprise at the quantity. 落ちてくる uses ~てくる for motion toward the speaker's location.