SE Asian String Book; Prayers, History or ?; ~75 Leaves

This is the second item from my friend, Anne. The cotton string is perhaps 10 feet long, and has a few knots in it. Each of the interior leaves is ~9" by ~1 1/4" by maybe .025", and is a piece of dried plant foliage that has a great many characters cut into each face. I am unfamiliar with the form of the characters, so they may be shown here upside down. Because I can see light through some of them, I initially thought the reverse of each leaf was mirrored from the front...but I no longer think that is so; seems that both sides are unique, so the 'story' (if it is one) occupies roughly 150 faces, each containing perhaps 200 characters...all hand-cut! Amazing really doesn't describe how this item feels to me...I've never seen the like, anywhere. Only one of the 75 or so leaves has what appears to be inked characters (pic 5); all the others are simply cut into each surface (like pic 6).

I'll follow this post with the rest of the pics.

 

The last 5 pics here are of a leaf that was split, allowing me to remove it from the binding string to get clearer shots of all 4 quarters. If you'll ID those that have the text inverted, I'll amend them & repost.
What language is represented? Is there a name for the 'alphabet', as with Japanese kanji, hiragana, katakana & etc.? Is it possible to determine the purpose of this collection of characters on plant leaves, center bound with string? Is this an unusual form of literature? Can a rough date or era be assigned to the item? An' lastly, is this a significant piece, or more common? As always, Thank You for lookin'!

 

It looks like an Indonesian Lontar book, or palm leaf book.
Lontar books are the traditional books of Java, Madura and Bali.
Similar books were used in mainland Asia.

It looks like an oldie, and it is worth having a scholar take a look at it. It is probably one volume of several, together they would be about a historical period, religious content, or a literary work.

About Lontar books:
https://sawidji.com/2022/06/16/lontar-our-ancient-books/

It is called Hanacaraka script, after the first letters, just like alphabet. Javanese, Sundanese (W. Java), Madurese and Balinese are different languages, but they were all written in Hanacaraka script.

Hanacaraka:
https://en.wikipedia.org/wiki/Javanese_script