You don't need a dinning room. That's a luxury feature.
It is possible to share bathrooms if you build housing more like school dooms or single room occupancy.
Having a place to eat at home is not a luxury feature, unless the city has a population density that is high enough to support having a broad array of dining options that are open for most of the day. Tokyo is one example of such a city, but having restaurants that are open 24x7 is not common at all in Europe.
Growing up (middle-class; both parents were teachers), we used our dining room to eat maybe 3 times a year. We ate around 1000 meals/year at the kitchen table and maybe 3 at the dining room table.
