what is table called in lua code example

Example 1: how to make a table in lua

--You need to use this {} and put them in a varible
local Table = {13,"1hihihi",
-- u can even do tis
{122,222}}

Example 2: table lua

a = {}
    x = "y"
    a[x] = 10                 -- put 10 in field "y"
    print(a[x])   --> 10      -- value of field "y"
    print(a.x)    --> nil     -- value of field "x" (undefined)
    print(a.y)    --> 10      -- value of field "y"