what does this phrase mean quaint with many a device in india ink?
It means that, whatever the subject is, it is interestingly odd, with a lot of black ink designwork.

I still couldn't understand meaning of that phrase so please explain me little further.
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what does this phrase mean ''quaint [= unusual] with many a device [= ornamental design] in india ink [= very thick black ink used for drawing']'?
(Whatever it is) was "unusual with lots of ornamental designs drawn in thick black ink"

quaint with many a device in india ink.

Couldn't we simply say quaint with many devices in india ink?
You can.
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That means:

many a device = many devices.

But how?
Jackson6612That means:
<>many a device = many devices
However, "many a" is used more in literary, even poetical, contexts than in informal ones.