Why are there issues creating many related records related in larevel?

Question

I have two related tables: table A and table B.

model a

public function comments(){
    return $this->hasMany('App\tableB');
}

model b

public function posts()
{
    return $this->belongsTo('App\tableA');
}

I want create a record in table A, then use it and insert many records in table B.

This code works :

$s = tableA::create(["postname" =>"test"]); // this create success

now I insert records of comments for this created post:

$s->comments()->createMany([["txt"=>"a"],["txt"=>"b"]]);

Question 1 :

I enabled query debug and see this code :

$s->comments()->createMany([["txt"=>"a"],["txt"=>"b"]]);

runs a query for each insert (i.e. insert into x values (a) and insert into x values (b ) and ........) !!!

How can the code be changed such that it will not run one Insert statement for each record?!

Question 2 :

I have a problem with passing an array to the laravel createMany() method :(.

How can this output [["txt"=>"a"],["txt"=>"b"]] be created with php?

I tried to create with below code but its not working and laravel shows an error

  $b = array();
        array_push($b,"txt","yellow");
        array_push($b,"txt","ssss");

Can anybody help me?

i want Exactly this : see the link (The createMany Method ) --- but it run multi query for each insertion

$post = App\Post::find(1);

$post->comments()->createMany([
    [
        'message' => 'A new comment.',
    ],
    [
        'message' => 'Another new comment.',
    ],
]);