I forgot that the style was still applied.
The first table is aligned by the Style (Normal + Centred)

The second table still has the Style applied but I have put Decimal tabs over each column and aligned to the left.

The net result is that the columns are aligned to the centre (or near enough) and all the decimal points line up.

I am running Word 2000.
If you are running Word XP it will probably give a slight change to the description of the style in the second table.

The important thing is the decimal tab.
You can add them by either double clicking in the horizontal ruler and selecting decimal Tab then typing the position you want.
Or you can click the tab icon (to the left of the horizontal ruler) several times until it looks like an inverted 'T' with a dot on the right.