Which ore is malleable: lead or tin?
This question depends on which ores of lead and tin you are curious about! In their pure forms, both lead and tin are malleable metals, but this isn't always so in their ore states.
First, let's address the mineral quality called tenacity. Tenacity describes how easily a mineral can be manipulated, ranging on a scale from being brittle (easily crushed when manipulated) to elastic (regaining shape after manipulation.) Malleable is second to brittle in tenacity, meaning a substance does not crush when manipulated, but that it requires some force to change its shape. Characteristic malleability would be a substance which can be hammered into a thin sheet, like copper.
Lead deposits occur commonly in nature, primarily found in the form of galena ore. Galena is quite brittle, but after smelting, the liberated lead is malleable. Other forms of lead ore like anglesite, boulangerite, and cerussite are also brittle.
Tin is surprisingly uncommon on Earth, and must be extracted from ore sources. Cassiterite is really the only useful (or abundant enough) ore from which tin can be liberated. Like lead ores, cassiterite is brittle, but the tin liberated during smelting is malleable.