Can I fix the width of a column in an org-mode table?

Per the org-mode manual, you can fix the width of an org-mode table column by putting <width> on a line somewhere in that table. I usually put it in its own line directly under the column headers, but anywhere in the column will work.

For example, here are the first two lines of a table:

| Citekey | Topic | Results |
| <15>    | <20>  | <40>    |

When the columns are next aligned, this will fix the width of the first column to 15 characters, the second to 20, and the third to 40. Content that exceeds the width of the column will be truncated with a => to indicate more content. Mousing over the field will show the full contents.

As mentioned by @Ryan you can use column width cookie <width>. But to make it working in Org 9.2+ you have to put #+startup: shrink in to top of the file or set variable org-startup-align-all-table to have this behaviour in all buffers by default.

(setq org-startup-align-all-table t)