I bought these table number holders off ebay last week:
I only tried them out tonight with my home-made table numbers today and they are too heavy for them, they just topple over when I attach them.
My table number cards are less than a5 but I stuck card back-to-back to make them double sided so that is where the weight is coming from.
I'm not sure what to do at this late stage, if i order more I may have the same problem! Any ideas?