I just wonder if there is a good expression to refer to an "easily readable book", like a simple short story or pocket book?
Consider a "Digest" (from Digest-sized)
Digest size is a magazine size, smaller than a conventional or "journal size" magazine but larger than a standard paperback book, approximately 5½ x 8¼ inches, but can also be 5⅜ x 8⅜ inches and 5½ x 7½ inches. These sizes have evolved from the printing press operation end. Some printing presses refer to digest-size as a "catalog size," such as that used by Avon Products when selling house to house. The digest format was considered to be a convenient size for readers to tote around or to leave on the coffee table within easy reach.
The most famous digest-sized magazine is Reader's Digest, from which the size appears to have been named.
Also, consider digestible adj.
(of information) easy to understand or follow.
verb (often as adjective abridged) Shorten (a book, film, speech, etc.) without losing the sense: an abridged text of his speech OED
I have seen abridged versions of lots of longer books such as Sherlock Holmes books that have been abridged to make them more appropriate for a younger more modern audience. However this probably doesn't apply to shorter books that have been written as simple books. I would call those 'light reading' or 'easy reading'.
What about pulp fiction? The term referring to fiction that was printed en mass, for consumption by a wide target audience. "Pulp" referring to the cheap paper it was printed on, to further facilitate the cost of mass-production.
And no, not the movie!
Every Book is readable in its own ways, it is whether we are worth of it or not ? Well, some books I found myself worth of were these ,
(starting from YA) Divergent Series The Fault in our Stars The hunger games series Percy Jackson books are brilliant Maze runner, of course Alchemist (an all age book, actually) Vampire Academy Series The trylle trilogy by Amanda Hocking Will Grayson, Will Grayson The perks of being a Wallflower The book Thief ( now the classics)
Pride and Prejudice Moking bird heart of darkness (to be honest, I did not read the entire book but only a short history on https://freebooksummary.com/achebe-heart-of-darkness-summary-12940 Diary of Anne Frank ( not a classic, but) Moby Dick The great gatsby ( The mystery)
Dan Brown books Sydney Sheldon Books Robert Ludlum Books Agatha Christie and anything else you like, these are a few, read personally I don`t have
A novella TFD (sometimes called a novelette).
- A short novel.