In your case what you would need to do is create a variable of type datatable in your main workflow. This is so that your main workflow can hold the datatable that will be passed around. Lets call it myDt. Next in your “Workflow1” Do whatever logic is needed to get the datatable and assign in to an out variable called “outVarMyDt”. for verbosity
Back in your main Workflow when you implement the “invoke workflow file” activity and you click “import arguments”, you should see the out var from that process.
In the space that is labeled “value” you can assign any local variable to the output of this workflow. And guess what? You already have one just for this. Its called myDt! Lets fill that out.
Now, the outputted datatable from “Workflow1” is assigned to your variable called myDt.
If you want to pass this datatable to another workflow, create that workflow, lets call it “Workflow2” within that workflow create an input var called inputVarMyDt
Back in your Main workflow, if you implement the “invoke workflow file” activity and click “import arguments” you will see this
now you can assign the variable called myDt that is within your main workflow to the input argument goin into “workflow2”
Don’t forget to save your workflows before trying to invoke them, sometimes it can be frustrating when you click “import variables” and you don’t see the variables that you declared because you forgot to save the workflow file.