Problem Definition

In Confluence Server/Data Center, there is no way to set a fixed width for the entire table, making it hard for the editor to align multiple tables in the same page nicely for easy reading.
This is because resizing each column's width would always impact the maximum table width as shown in the screenshot below:

When there are more tables in one page, it quickly becomes a very tedious job for the editing person to align each of the tables in order to have the same column/table width if they'd want to have every table sharing the same width/layout.

Confluence Cloud on the other hand, always have the Table Width set to a fixed width so resizing the columns will not impact the maximum table width. This allows the editing person to be able to form a unified table structure across the entire page:

Suggested Solution

Allow editor to configure the width of each column and table so the editing person can easily unify the table structure using absolute numbers rather than dragging with the cursor.
Refers to the Workaround below, but having a proper UI for this instead

Workaround

Install Source Editor and edit the source manually to set Table Width and Column Width: