I've found most restaurants I go to very helpful and accomodating. Wetherspoons are lovely and there are also some nice starters to have as main courses too, as in most restraunts. Toby Carveries will let you have a toddler plate so you can take food off someone elses plate. My kids aways dish themselves up more than they can manage so this works perfectly. Pizza hut is great too as there is plenty of salad and you can order a childs meal. Most places are fab and like I said before, if they wont accomodate you then just choose one of the lovely starters and ask for it to be served with everyone elses main course.
Ha ha in Wetherspoons last week (Tim and I go there every Thursday for dinner) I had chicken in the fridge that needed eating so I took it with me, ordered a side salad for 80p took half out into my box then added the chicken to the bowl and my extra light mayo (I carry that in a little tub) and Bobs your Uncle. No one saw, no one would have cared anyway and I had what I fancied to eat while Tim ate a great hunk of steak and scampi with chips, minus the 3 chips I nicked.
I always take a Tupperware box in my handbag when we eat out as I can never eat everything on my plate and if I don't eat it the dog does.
Kate x