The games inventory management is abysmal which i have just posted about in suggestions, to see if we can get Larian to fix it..
On the chance they won't (All DOS2 DE support/patches seem to have stopped... so..) Maybe a mod may do this?
There are a couple of ideas..
1: Fixing the Bags mod that is on workshop that sort of does this, but the mod is broken.
2: Modding the Gift bag of Larian's 'inventory organisation' mod to fix it to allow working in crafting and selling etc.
3: Somehow enabling Multi-select for Keyboard/mouse (There is an option for this on controller.. maybe theres a way to enable it via a mod?)
What are your thoughts?