午餐或任何簡餐（輕食）

午饭, 各种简餐, they'll know your slogan. good luck!

If it's a slogan, and aiming to be understood or even praised by Chinese , you could just make it like 午餐与轻食，which is very concise if he or she means there are both inside the restaurant. Even there's an ''or'' , I still don't think you should have added an ''或''. Because when it comes to the meaning of you could do either way inside the restaurant. We would just say ''和'' to make it sounds bigger . Just personal opinion as a native speaker. Chinese love to make their image full. Hope it helps.

The translation is okay, but it's word to word translation and can't be used as a slogan.

correct 午饭，或者便饭