Thanks Pipke!
After adding this meta I got the following preview in the DevTools which is, I suppose, even more strange.
I thought it could be related to the custom font DPI (125%) which I set in my Windows, but nothing changed after setting it to the default 100%.
Also, in my desktop Chrome shortcut I have the following target command:
"...\chrome.exe" /high-dpi-support=1 /force-device-scale-factor=1
I launched Chrome without this addition but it didn't change anything either.
The fact is that the GigaWatt's site always looks good in DevTools.
Never mind, let's say it is something mysterious

The most important thing is that the site (and the RFT table) looks OK on most mobile devices.