I am looking for a cheap restaurant in the centre part of town.
You have lots of good cheap choices in that part of town!  What type of food sounds good to you? There are Italian restaurants, Indian, Spanish, Chinese, and more.
How about Chinese? can you book me a table for 3 people at 18:15 on a Sunday?
I'm sorry, none of the Chinese restaurants are available at that time. Is there another day or time that would work for you?
Ok, I'll try for a little earlier, how about 17:15?
Booked at Charlie Chan! Your table will be reserved for 15 minutes. Reference number is YGWCXMK4.
Thanks so much. I think that was all I needed. Have a great day. 
Thank you. Enjoy your meal.