>>And then we come to more interesting cases, like vegetable, crucible, cable, amicable, stable, table, gable, fable, and syllable. Must have been interesting verbs, before they were lost :).
>
>Many of them would be the same in French, eg table, syllable.
>
>Amicable I guess would be able to "amare".
>
>By your reckoning then, all plural of nouns makes them also into the 3rd person singular of verbs?

Tom Hanks? He surely does.

>And any word ending in "er" means the person who performs it? eg a letter is a person who letts?

Just like a crater is the guy who makes crates, n'est pas? :)