Hi Sebastian,
There are 2 techniques how to apply a calculation to all columns:
Unpivot, Calculate, Pivot back
It's simple and works well on small tables. Unpivot your table so that values of all columns become one column, do the calculation using one expression and one action, then pivot it back. See the example here:
And here:
Use the Iterate Column action
The "Iterate columns" action is designed exactly for complex table-wide operations. Unlike the regular "Iterate" action, "Iterate columns" iterates not across rows, but across columns.
This technique is more difficult to understand than the 1st one, however, it allows dealing with very large tables with hundreds of millions of data points, and rather complex scenarios.
See documentation here: transformations:iteratecolumns [EasyMorph Help]