I'm not exactly picturing your App, so this might be tricky, but, if I understood correctly, it is that you want your gallery to show X thing if there are records in 'PMO - Scorecard' and in case there are no records, you want your gallery to show Y thing...
If that’s right, then you have two ways of going about it:
First, if the contents of the gallery are wildly different, like, the contents of X have nothing to do with the contents of Y regarding the columns they must show. It is easier to just have two galleries, and just switch between them, showing one or the other for each case.
Second, this works for both if the contents are the same or wildly different, although it’s a pain in the ass to set up the contents are different. But you can just have some logic in the Items property of your gallery, check if there are any records in the 'PMO - Scorecard', and in case there are, you show X items, and in case there aren’t you show Y items. If the columns are the same for both tables, then it’s pretty much easy to set up, if they’re different, you’ll have to have logic for each individual control within the gallery, to account for this possibility.
Hopefully I made myself clear and I made sense to you!