If you want to make a list of coordinates, so that you will spawn at one position of multiple positions defined, you can do that in this way:
spawn_pos =
{
{x1,y1,z1},
{x2,y2,z2},
...
}
To get random coordinates:
x,y,z = unpack(spawn_pos[math.random(#spawn_pos)])
And you can use x,y,z in spawnPlayer.