JSFiddle - React, Tailwind, and code Playground

HTML

<table id="students" border="1">
    <thead>
        <tr>
            <th>Name</th>
            <th>Age</th>
            <th>Grade</th>
        </tr>
    </thead>
    <tbody>
        <tr class="student">
            <td>Oscar</td>
            <td>23</td>
            <td>16.5</td>        
        </tr>
        <tr class="student">
            <td>Antonio</td>
            <td>32</td>
            <td>14</td>        
        </tr>
        <tr class="student">
            <td>Jessica</td>
            <td>21</td>
            <td>19</td>        
        </tr>
    </tbody>
</table>

JavaScript

var tblhdr = $('table#students th').map(function () {
    return $(this).text();
}).get();

console.log(tblhdr);

var tbl = $('table#students tbody tr').map(function(idx, el) {
    var td = $(el).find('td');
    var obj = {id: idx+1};
    
    for (var i = 0; i < tblhdr.length; i++) {
        obj[tblhdr[i]] = td.eq(i).text();
    }
    
    return obj;
}).get();

console.log(tbl);