JSFiddle - React, Tailwind, and code Playground

HTML

<table class="content">
    <tbody>
        <tr>
            <th>head1</th>
            <td>value1</td>
        </tr>
        <tr>
            <th>head2</th>
            <td>value2</td>
        </tr>
    </tbody>
</table>
<table class="content">
    <tbody>
        <tr>
            <th>alpha1</th>
            <td>value4</td>
        </tr>
        <tr>
            <th>alpha2</th>
            <td>value5</td>
        </tr>
        <tr>
            <th>alpha3</th>
            <td>value6</td>
        </tr>
    </tbody>
</table>

JavaScript

function createJSON(){
    var self = this;
    self.thejson = {};
    $('.content tr').each(function(index, value){
        var k = $('th', this).text(), v = $('td', this).text();
        self.thejson[k] = v;
    });
    return self.thejson;
}

console.log(createJSON());