This is how an author submits a book to a publisher or agent. It's far easier to read than a single-spaced A4 page - and most editors do their reading on the bus or train, or in bed. When a book is taken on by a publisher, it is edited and typeset as you see in a finished book.
Here are some FAQs about approaching publishers from the home page of my website:
Firstly, get in touch with the publisher. Find their phone number and/or address and ask if they are accepting unsolicited scripts (some publishers simply don't), and if so, what they would like to see: a synopsis and the first few chapters, or a complete script. Never send chapters from different places in the book. This will result in your script being returned immediately. And if you think ‘Oh, but it gets better later, the opening isn't my best writing,' then make it your best writing. Apart from interesting the publisher, your opening has to interest readers. If someone picks up a book and is not interested in the first ten pages, they'll put it down again, nine times out of ten.
There are also basic presentational matters: Double space your script. Do not print on both sides of the paper. Do not bind the script in any way, chapter by chapter or as a whole. Publishers simply find this irritating. Put a couple of rubber bands around it (or a paperclip), and nothing more. Set the first paragraph in each new section, after a line-break, full out. Do not add a double line-break between paragraphs and set them all full out. Basically, have a look at a finished UK novel and see how it is set out – that's how you should set your script out, with the exception of double spacing (if you're in the United States, do the same with a US novel). Expect a four to six week wait for a reply, at least.