Existential or Locative

[Rika]

Hello!

It is generally said that existential "there" sentences like (a) convey new information, so they usually occur with indefinite articles "a":
(a) There is a book on the table.

But there are also sentences like (b), which occurs with the definite article:
(b) There is the book on the table.

Obviously (b) doesn't convey new information.
I think that's because (b) is a locative (demonstrative) "there" sentence, not an existential "there" sentence.
Is it right?
If so, "there" in the sentences with the definite article are all locative?

And also, true to its name, existential "there" sentences are used when you describe the existence of something, and often include a locative word (like "on the table" in (a) ), so I think existential "there" sentences have something to do with locative "there" sentences.

What do you think of my idea?

[Englishcool]

Do you think this sentence is right ? -- There is the book on the table.
I don't think so. I have learned this sentence is wrong. So, it must be changed into 'The book is on the table.'
We can't use 'There is/are ~' in this stentence because the subject is not new information.

It is very hard to express my ideas in English fully, as English learner as foreign language.

Good Luck!