[REACT] Warning: validateDOMNesting(...): Whitespace text nodes cannot appear as a child of <tr>. Make sure you don't have any extra whitespace between tags on each line of your source code.

결론 : 코드 사이에 모든 공백을 제거하면 더이상 콘솔경고 나지 않음

ex ) 

<tr> <th > {head}    </th> </tr>

<tr><th>{head}</th></tr>

콘솔 경고창