学艺不精，前来献丑，请广大网友指正【总感觉最后一行continue好像有点多余呢，因为第一行的True代表了它永远不会在while的时候判断为False跳出循环】 
while True:
    print("Welcome! How many people, please?\nEnter 'quit' to end the program.")
    i = input()
    if i=='quit':
        break
    elif int(i)<=4:
        print('Your small table is reserved!')
    elif 4<int(i)<=6:
        print('Your middle table is reserved!')
    elif 6<int(i)<=10:
        print('Your large table is reserved!')
    elif int(i)>10:
        print('Sorry, there is no free table that seats over ten persons.')
    continue