datatable.directory/app/Http/Controllers/TableController.php

<?php

namespace App\Http\Controllers;

use App\Models\Table;
use Illuminate\Http\Request;

class TableController extends Controller
{
    /**
     * SHow a form for creating a new table
     *
     * @return \Illuminate\Http\Response
     */
    public function create()
    {
        $exampleColumns =
            "latin, string, Latin Name\n".
            "common, string, Common Name\n".
            "lifespan, int, Lifespan (years)";

        $exampleData =
            "Mercenaria mercenaria, hard clam, 40\n" .
            "Magallana gigas, pacific oyster, 30\n" .
            "Patella vulgata, common limpet, 20";

        return view('table.create',
            compact('exampleColumns', 'exampleData')
        );
    }

    public function storeNew(Request $request)
    {
        $u = \Auth::user();

        $this->validate($request, [
            'name' => 'required',
            'title' => 'string|nullable',
            'description' => 'string|nullable',
            'license' => 'string|nullable',
            'upstream' => 'string|nullable',
            'columns' => 'required',
            'data' => 'string|nullable',
        ]);

        // Check if table name is unique for user
        $name = $request->get('name');
        if ($u->tables()->where('name', $name)->exists()) {
            return back()->withErrors([
                'title' => "A table called \"$name\" already exists in your account.",
            ]);
        }

        return "Ok.";
    }
}