This is somewhat incorrect. It is also a research facility. As long as you call to make an appointment to do so, you may use the vast library for research purposes. There is also a cafe, and during the daytimes, when it's not busy, you can avail yourself of a table, order a beverage and work on your laptop. They have wi-fi. Many scholars and researchers use the library everyday. It's probably better if you get a membership, which also entitles you to uncharged access and other benefits. https://www.themorgan.org/visit/hours-and-admission
This isn't a "library" you can go to sit and study. It's a private home of financier JP Morgan that was converted into a museum. They have an auditorium and cafe and exhibitions (along with books from JP Morgans collection). If you need a study carrel desk with outlets for laptop I recommend NYPL - Science Industry Business Library on 32nd and Madison (a short walk from The Morgan) they have carrels with outlets and a great place to study.
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