user12311: Each file is around 350-650 MB.  
This is the media information from the Files:  
https://i.imgur.com/FqchDMi.png 

How could I better archive it? 
Easily convert & archive a bunch of low res Video CD DAT files MPEG 1/2 to newer better format such as MKV or others?  

user1950: When you say archive, do you mean for long-term storage, such as in a library or museum? If that's the case a lossless, well-documented, open-source codec and container is what you want. FFV1 in a matroska continer (.mkv file) is my preferred archival codec / container format, and it's gaining popularity in the GLAM sector.
Once again, FFMPEG is the tool of choice for making these–FFV1 is a codec developed by the creators of FFMPEG. A good page on how to encode FFV1 here, and an example would be:
ffmpeg -i input_video.dat -c:a pcm_s16le -c:v ffv1 -level 3 -coder 1  -context  1  -g 1  output.mkv 

For archival purposes I would not de-interlace because of the loss of resolution, and because it alters the source substantially.

user1871: Using ffmpeg, a free command-line tool, you can convert these DATs to MP4 (or MKV):
ffmpeg -i input.dat -c:v libx264 -crf 20 -c:a aac -b:a 128k -movflags +faststart output.mp4

Your VLC output doesn't mention it but if the inputs are interlaced (likely), then use
ffmpeg -i input.dat -vf yadif -c:v libx264 -crf 20 -c:a aac -b:a 128k -movflags +faststart output.mp4


12311: <p>Each file is around 350-650 MB.  </p>

<p>This is the media information from the Files:  </p>

<p><a href="https://i.imgur.com/FqchDMi.png" rel="nofollow noreferrer">https://i.imgur.com/FqchDMi.png</a>  </p>

<p><a href="https://i.stack.imgur.com/DLeSw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DLeSw.png" alt="enter image description here"></a></p>

<p>How could I better archive it? </p>

<p>Easily convert &amp; archive a bunch of low res Video CD DAT files MPEG 1/2 to newer better format such as MKV or others?  </p>
 1950: <p>When you say archive, do you mean for long-term storage, such as in a library or museum? If that's the case a lossless, well-documented, open-source codec and container is what you want. FFV1 in a matroska continer (.mkv file) is my preferred archival codec / container format, and it's gaining popularity in the <a href="https://en.wikipedia.org/wiki/GLAM_(industry_sector)" rel="nofollow noreferrer">GLAM</a> sector.</p>

<p>Once again, FFMPEG is the tool of choice for making these–FFV1 is a codec developed by the creators of FFMPEG. A good page on how to encode FFV1 <a href="https://trac.ffmpeg.org/wiki/Encode/FFV1" rel="nofollow noreferrer">here</a>, and an example would be:</p>

<pre><code>ffmpeg -i input_video.dat -c:a pcm_s16le -c:v ffv1 -level 3 -coder 1  -context  1  -g 1  output.mkv 
</code></pre>

<p>For archival purposes I would <em>not</em> de-interlace because of the loss of resolution, and because it alters the source substantially.</p>
 1871: <p>Using <a href="http://ffmpeg.org/download.html" rel="noreferrer">ffmpeg</a>, a free command-line tool, you can convert these DATs to MP4 (or MKV):</p>

<pre><code>ffmpeg -i input.dat -c:v libx264 -crf 20 -c:a aac -b:a 128k -movflags +faststart output.mp4
</code></pre>

<p>Your VLC output doesn't mention it but if the inputs are interlaced (likely), then use</p>

<pre><code>ffmpeg -i input.dat -vf yadif -c:v libx264 -crf 20 -c:a aac -b:a 128k -movflags +faststart output.mp4
</code></pre>
