memo pad; notepad; scratch pad
A small pad or notebook for jotting down quick notes, reminders, or ideas.
I wrote the phone number down in my memo pad.
I jotted down ideas on a memo pad during the meeting.
There is a notepad and a pen on the desk.
He took a memo pad out of his pocket.
She always carries a memo pad with her.
メモ帳 is the everyday word for a small notebook, while パッド (as in メモパッド) specifically suggests a pad of tear-off sheets.
counter for books; counter for volumes · volume; book
Compound of メモ (memo, from English) and 帳 (notebook, register).