I had tried to re-arrange the tab order in the table, but it fail to do so.
As the default tab order is by row.
I would like to set the tab order by column.
I had set it in the tab palette, but it fails. It will auto reverse to the original tab order.
With your supplied form you wont be able to add the header to the tab order unless there is a user entry field there. Changing the tab order of the rest wasn't an issue for me.
The Header Row might be the problem. I deleted it and added another row where it was and then i could reorder without an issue. I changed it's type to Header Row and was still able to set the tabs ok.