What's a table for one? I've never seen that. The tables where I live go in even numbers: 2, 4, 6, 8, etc. I can't even imagine a table with just one side.
Some cafes I go to have tables that are ostensibly for 2 but because of the layout, or the way other tables are occupied, it would be impossible for two people to comfortably sit at it. Equally some places have a "bar" style set up or larger communal tables where single patrons can sit in the cafe without taking up more places, especially when its busy.
I think it might do you good to get used to being alone in a cafe to be honest. It's a pleasure in itself and there's no need to think about it in terms of wasted money.
I am perfectly happy being alone in a cafe when I choose to go to one. Not when I am only there because someone else wanted to go there. It is not a pleasure if you are not someone who enjoys sitting in a cafe alone waiting indefinitely. I happily walk alone, go shopping alone, eat out alone but that doesn't mean I cant resent being forced to sit somewhere alone when I am supposed to be there with someone.
As for wasted money, I am a single parent earning not much more than minimum wage, I can't afford to just buy overpriced coffee for the sake of it. Going out for coffee with a friend is an expense I am happy to work into my budget as a treat, but I wouldnt routinely go to Costa/Starbucks etc and pay over the odds when I can make the same drink at home. So if my friend leaves me waiting, I will spend money on a coffee that I otherwise wouldnt have bought (so as not to feel awkward taking up a table without actually being a customer), and then when they do turn up I feel obliged to buy another drink/snack so I am not just sitting there watching them drink while I sit there with the dregs of my "waiting" coffee.