With the heavy weight, I wouldn't dare attach the memo board with nails only.

We first fixed the memo board in the kitchen with door hooks above the kitchen combination (something like this: https://www.galaxus.ch/de/s14/product/relaxdays-tuerhaken-garderobe-kleiderhaken-13981754) and attached cords to them. This held well and we didn't have to drill any holes in the kitchen of the rented flat.