For 2 pictures:

<table><colgroup> <col style="width: 50%;" /> <col style="width: 50%;" /></colgroup>
<tbody>
<tr>
<th><center><b>Dreamcast</b></center></th>
<th><center><b>Gamecube</b></center></th>
</tr>
<tr>
<th><a href="" target="_blank" rel="noopener"><img align="center" width="100%" height="100%" src="" /></a></th>
<th><a href="" target="_blank" rel="noopener"><img align="center" width="100%" height="100%" src="" /></a></th>
</tr>
</tbody>
</table>

For 3 pictures:

<table><colgroup> <col style="width: 33%;" /> <col style="width: 33%;" /> <col style="width: 33%;" /></colgroup>
<tbody>
<tr>
<th><center><b>Dreamcast</b></center></th>
<th><center><b>Gamecube</b></center></th>
<th><center><b>PC</b></center></th>
</tr>
<tr>
<th><a href="" target="_blank" rel="noopener"><img align="center" width="100%" height="100%" src="" /></a></th>
<th><a href="" target="_blank" rel="noopener"><img align="center" width="100%" height="100%" src="" /></a></th>
<th><a href="" target="_blank" rel="noopener"><img align="center" width="100%" height="100%" src="" /></a></th>
</tr>
</tbody>
</table>

3 vids

<table><colgroup> <col style="width: 33%;" /> <col style="width: 33%;" /> <col style="width: 33%;" /></colgroup>
<tbody>
<tr>
<th><center><b>Dreamcast</b></center></th>
<th><center><b>Gamecube</b></center></th>
<th><center><b>PC</b></center></th>
</tr>
<tr>
<th><div style="position:relative;height:0;padding-bottom:75%"><iframe src="https://www.youtube.com/embed/vwF1tRSXNIM?controls=0&amp;showinfo=0&loop=1&playlist=vwF1tRSXNIM" style="position:absolute;width:100%;height:100%;left:0" width="630" height="360" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe></div></th>
<th><div style="position:relative;height:0;padding-bottom:75%"><iframe src="https://www.youtube.com/embed/fNuRELVTHFc?controls=0&amp;showinfo=0&loop=1&playlist=fNuRELVTHFc" style="position:absolute;width:100%;height:100%;left:0" width="630" height="360" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe></div></th>
<th><div style="position:relative;height:0;padding-bottom:75%"><iframe src="https://www.youtube.com/embed/fNuRELVTHFc?controls=0&amp;showinfo=0&loop=1&playlist=fNuRELVTHFc" style="position:absolute;width:100%;height:100%;left:0" width="630" height="360" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe></div></th>
</tr>
</tbody>
</table>

2 vids

<table><colgroup> <col style="width: 50%;" /> <col style="width: 50%;" /></colgroup>
<tbody>
<tr>
<th><center><b>Dreamcast</b></center></th>
<th><center><b>Gamecube</b></center></th>
</tr>
<tr>
<th><div><div style="position:relative;height:0;padding-bottom:75%"><iframe src="https://www.youtube.com/embed/vwF1tRSXNIM?controls=0&amp;showinfo=0&loop=1&playlist=vwF1tRSXNIM" style="position:absolute;width:100%;height:100%;left:0" width="630" height="360" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe></th>
<th><div style="position:relative;height:0;padding-bottom:75%"><iframe src="https://www.youtube.com/embed/fNuRELVTHFc?controls=0&amp;showinfo=0&loop=1&playlist=fNuRELVTHFc" style="position:absolute;width:100%;height:100%;left:0" width="630" height="360" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe></div></th>
</tr>
</tbody>
</table>(edited)


for single videos, use this:
<center><iframe src="https://www.youtube.com/embed/ENYe1PKJL_0?controls=0&amp;showinfo=0&loop=1&playlist=ENYe1PKJL_0" width="640" height="480" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe></center>