Python Tabulate - How to print vertically list with values from an input

I am making a console program in Python where the user can add multiple values ​​to multiple lists and create a contact book. I already have all the data in a different list, now I need to print this data in a table, with the TABULATE module.

I can print this data, but it is not as if I want to show the user their contact book, since when printing, the table shows me the NAMES field in a vertically single row with all the names separated by commas, and not one below the other as it should be.

How can I fix this? (In the main list, are the merge between names and lastname, which are some of the data I wanted to print.

from tabulate import tabulate
start = True
names = []
lastnames = []

while(start):
        print("***************************************")
        print("1: Add the contact name: ")
        print("2: Add the lastname for the contact: ")
        print("")
        op = input("Which option you want to do?: ")
        if(op == "1"):
                print("\n ADDING")
                name = input("Please, type the name of the contact: ")
                names.append(name)
                lastname = input("Now, please type the lastname: ")
                lastnames.append(lastname)
                print("")
        if(op == "2"):
                print("EXIT")
                start = False

nameStr = "".join(names) # Get the list in a str
lastStr = "".join(lastnames) # Get the list in a str
mainList = [[nameStr, lastStr]] # Main list, with the str data
heads = ["NAMES: ", "LASTNAMES: "] # Headers to the tabulate module
print(" ")
print(tabulate(mainList, headers=heads, tablefmt='fancy_grid', stralign='center'))

Then I get this list:

You should pack both the first name and the last name into a single list for each individual and then append that list to names list:

from tabulate import tabulate
start = True
names = []

while(start):
        print("***************************************")
        print("1: Add the contact name: ")
        print("2: Exit ")
        print("")
        op = input("Which option you want to do?: ")
        if(op == "1"):
                print("\n ADDING")
                name = input("Please, type the name of the contact: ")
                lastname = input("Now, please type the lastname: ")

                names.append([name, lastname])
                print("")
        if(op == "2"):
                print("EXIT")
                start = False

heads = ["NAMES: ", "LASTNAMES: "] # Headers to the tabulate module
print(" ")
print(tabulate(names, headers=heads, tablefmt='fancy_grid', stralign='center'))

 
╒═══════════╤═══════════════╕
│  NAMES:   │  LASTNAMES:   │
╞═══════════╪═══════════════╡
│   Louis   │     Smith     │
├───────────┼───────────────┤
│  Gerard   │    Taylor     │
╘═══════════╧═══════════════╛