IOS – Cannot overwrite columns in Numbers for iPad

Long text when Wrap text in cell is turned off does not merge with the next cell, it simply overlays on top of the adjacent cell if the adjacent cell is empty. Numbers just hides the borders for readability. If the adjacent cell has content, the text hides behind it.

There is no way, unfortunately, to expand the width of the cell to fit without expanding the width of the entire column.

Experiment with the text wrapping to get your desired result.

Hope this is useful!

EDIT (Complete revision):

Based on your data, the only way to accomplish this without redesigning the table is to create separate charts for each Segment shown. As each segment has 4 pieces of data, this is the only way to do this. (There may be someone out there who is a charting expert that could do much better, I'm sure)

First, as you have done is to make a Total chart:

Then crate separate charts, positioned together for the segments:

The charts can be edited for looks and data views in the Inspector but that is beyond the scope of the question.