Puppetry assets (targets, groups, test cases, test steps, variables, snippets) have the same management interface based on data-tables.
To add a new asset you need to fill in the empty field(s) at the end of the table and press Add button next to it:
Alternatively you can add an asset to a particular position. Just hover the target record and right-click for the context menu. Select Insert item.
To edit an asset, click on Edit link next to the target record, provide new value and click Save button.
If you need a sequence of similar assets, you don't need to create each one from the scratch. Instead you clone one and adjust parameters of the clones:
To remove an asset, click on Remove link next to the target record. Choose OK for confirmation.
If you don't want to remove an asset, but temporarily exclude it for test run, hover the target record and right-click for the context menu. Choose Disable item:
You can use drag & drop to move assets:
You can copy/paste any of assets:
Besides, you can copy an asset in one suite/project and paste it in another. In fact, you can even copy an asset, save it in a text file and paste it later when you need it: