You can adjust the width of a table inserted into a CMS article item's rich text property (body) from the Design Editor.
Adjusting the overall table width
In the Design Editor, open the CMS article page (dynamic page) where the table is placed.
Select the <table> element (the entire table) whose width you want to adjust.
In the right panel, select the [Box] tab. If the panel is closed, open the right panel.
Adjust using the [Width] setting under the [Layout] menu.
The available size units are px, % (percent), auto, and vw.
Adjusting the width of cells within a table
In the Design Editor, open the CMS article page (dynamic page) where the table is placed.
Select the table header (th) or cell (td) whose width you want to adjust.
In the right panel, select the [Box] tab. If the panel is closed, open the right panel.
Adjust using the [Width] setting under the [Layout] menu.
The available size units are px, % (percent), auto, and vw.
You can't set widths on a per-column basis.