This would not work. Toad DevOps Toolkit does not work like this.
If you want to compare two specific tables (one in each schema), it is better to use CompareMultipleTables where you can add table mappings e.g. like this:
$TDT.CompareMultipleTables.TableMappings.Add('DEMO_TABLE=DEMO_TABLE')
You need to read names from the files and use them like this (e.g. read them from file in a loop), or if this mapping is not provided the all tables with matching names are compared.