TOPIC:

In the case that layout style is table, width % configuration will be easy to process. On the other hand, if layout style is responsive, how width % configuration is processed with PC?
Width % configuration is bellow in the subject site.
Date Column Width in % : 15%
Title Column Width in % : 55%
Venue Column Width in % : 15%
Category Column Width % : 15%

Joomla 3.10.11
JEM 2.3.3

For the responsive styling, it is important to read the instruction for responsive in the help sites of JEM!

What is the minimum width for responsive design?
It's best to make your website at least 1920px wide.
A 1280px website will look great on laptops and mobile devices but not so great on large monitors. To ensure your site looks just as good on big screens as it does on small screens, set your max site width to 1920px or more.