pustaka
The pustaka (पुस्तक) is a book of palm-leaves cut long and narrow or a manuscript which looks like one.
In Buddhist tradition, it represents the Prajñāpāramitā scripture of Transcendental Wisdom. This book is supposed to have been given by the Buddha to the Nagas for safe keeping.
Nāgārjuna recovered it from them and founded the Mahāyāna school on its teachings. The pustaka is the symbol of Mañjuśrī, Cundā, Prajñāpāramitā, etc.
Pustaka on padma
The Hindu God Brahmā holds a sacred manuscript in one of his hands. It is the symbol of wisdom.
Pustaka on Padma is a book on lotus.