Long keywords are cut on keywords list.
I think full keyword should be added on html title attribute for seeing the full keyword on mouse over, as seen on screenshot attached.
Note: only for long keywords, do not show always.
If someone says me which php file is that, I can do it.
It's not a PHP file. The truncation and tooltips are generated on the client/browser.
Take a look at plugins/CoreHome/templates/datatable.js