It sounds like you are not sure how many data columns you will have. If the table will look like your example (but with more columns), I think using the Tables > Stack command makes the most sense.
Put all of your data columns into the Stack Columns field. Click OK. Right-click on the Data column header and choose New Formula Column > Transform > Absolute Value. With this new table now choose Tables > Split. Specify the Abs{Data] as the Split Columns. Put the Label column in the Split By field. Make sure the Drop All radio button is selected and click OK.
You should have a table that looks like the original, but with no negative values.
Dan Obermiller