@benroyce
In my family, we always called them "bus stop books". They were the compact books that fit in a purse or pocket, something to read while waiting for or riding the bus. My dad always had one with him to read aloud to us when we rode the bus downtown with him, so we all picked up the habit as kids.
I wrote about Bus Stop Reading once on my book blog, with a paragraph specifically remembering some of my dad's favorite little pocket paperbacks.
Bus Stop Reading
The Invitation: My sister Meg sent me this invitation: If many people were to all post a short Something about how, where, what, why they like to READ it would be a Nice Thing and encourage others as well. We could share our own thoughts on secret public spaces for reading, beautiful free peaceful public…
Maria's Books (mariasbooks.wordpress.com)