No blotter cannot be used to mean planner. A blotter is a device for holding blotting paper. If a similar device is being used to hold a planner, it is no longer a blotter, even if it is exactly the same piece of cardboard and fake leather. It is a planner. You might have found "desk planner blotter", but that just demonstrates how ineffective an internet search is at finding good use of English. What you should have found is "desk planner/blotter" - something which can be used for one of these purposes, but not both at the same time.I only remember desk planners that looked like the jotters you describe. I found one online and it's called a "desk planner blotter." I was surprised at the name, since it was no blotting paper, but I see online that blotter can be used to mean planner! The things you learn!