Hi,
this is not possible or at least not easily via GUI.
Here are some possible solutions:
1. Prevent yourself from adding items outside of your desired filesize range in the first place:
Setup filters or views for your linkgrabber see Settings -> Linkgrabber Filter
This won't have any effect on items that are already in your downloadlist!
or:
2. For items that are already in your downloadlist:
You could create a custom EventScripter script which then e.g. removes- or disables all unwanted files with a click of a button.
EventScripter forum thread:
https://board.jdownloader.org/showthread.php?t=70525
EventScripter help article:
https://support.jdownloader.org/Know...event-scripter
-psp-