Try Stadslokaal Burgerzaken. Excellent spot for lunch, dinner, or just a coffee or glass of wine. If you sit all the way in the back, there might be some free wifi.
Near Windmill de Valk, there's a small takeaway 'toko' called Iboe Tjilik, which happens to sell the best Indonesian food in town. If you're there on a Thursday or Friday, be sure to try their Nasi Koening (yellow rice with rendang and more). Most excellent. There's 1 (just one) table if you don't want to order takeaway.