It would be great if we could easily pause tabs from updating, to look at something before it changes. This can be done by setting the tab refresh rate to 0, but that's too arduous to do often.
Not so sure if this feature really falls in the scope of a system monitor... Some suggestions: 1) you can easily extend the time period shown in ksysguard: right click on graph, settings, scale -> pixels per time period, lower it to your liking. I have it set to 1, that way you can easily span a period of 10 min on an FHD screen on full width. 2) do a screenshot instead :-)
I'd like to second this feature request. The atop command provides this with 'z', and in conjunction with filtering it is highly useful for examining short-lived or rapidly changing processes. As a workaround for ksysguard, it is possible to use 'kill -SIGSTOP' and 'kill -SIGCONT', but switching to a terminal to do this is a bit of a hassle and since the GUI loses all interactivity it's really no better than taking a screenshot. Particularly in conjunction with the ability to quick search, the ability to pause on a particular snapshot of the process table would be quite useful.
ksysguard is no longer maintained, in Plasma 6 there is the Plasma system monitor for this task. If your wish is still valid for the Plasma 6 replacement, please re-open and we can move this bug to the new product, thanks!