Every table, regardless of the type, could have this. For every user individually, start maintaining a list of column mappings for the tables that they care to customize. So, for example, next to each table that I view, we could have a button that opens a dialog, which then lets me rename columns to my liking. This should be saved in the database only for the user that defined such mapping.

I understand that most tables are displaying issues, and that the question of how to treat global columns (issue properties) would come up: the answer should be, apply globally (per user).

An example: if it bothers me that the column displaying a version number is too wide only because of its long name, I would rename it (by abbreviating); so, instead of "Targeted Version" I could have just "Target" or "tgt-ver", and I will then probably stopped being bothered by how wide that column is.

Another subfeature: while the user is renaming the column, allow them to force a line-break. So, for example, I might dislike abbreviated names, so instead of "Targeted Version", I'd like to force "Targeted<br/>Version" (syntax can be invented), and I'll be happier to see that column less wide (while the title row/bar would become taller).