Lite wallets aren't really consuming much space of your computer. But those wallets that downloads the whole blockchain network of that altcoin requires much space.
Did I answered your question somehow?
Not really!
But this is partially my fault, I was not precise enough. I am talking about the regular Qt wallets.
I would like precise figures because I have spare computers and I would like to dedicate one to host wallets.
However one is way more powerful than the other.
Hence I would prefer to use the weaker one - but still equipped with an i5 CPU and 8 GB of RAM - to keep the other one for an other purpose.
But to know for which one I should go for, I need to know if the 30+ wallets that will be running on it will not weigh too much for the weaker computer.