Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
con-tăbŭlo, āvi, ātum, 1, v. a., to furnish or cover with boards (several times in the histt.; elsewh. rare): turres, Caes. B. G. 5, 40: turres contabulatas machimentaque alia quatiendis muris portabant, i. e. built in stories, Liv. 24, 34, 7: pomaria, Plin. 15, 16, 18, § 59: totum murum ex omni parte turribus, Caes. B. G. 7, 22: pavimentum quernis axibus, Plin. 36, 25, 62, § 187: mare molibus, to furnish with a bridge, to bridge over, Curt. 5, 7, 8; cf. Hellespontum, * Suet. Calig. 19.