input: Write a function to generate a multiplication table with numbers in a given range defined by start and end parameters. 
  assert multiplication_table(1, 3)
  assert multiplication_table(2, 4)
  assert multiplication_table(3, 5)
output: def multiplication_table(start, end):
      table = []
      for i in range(start, end + 1):
          row = []
          for j in range(start, end + 1):
              row.append(i * j)
          table.append(row)
      return table