To add items its a very simple step.
For this part you need to follow a few steps:
1. To add emails
...
If you want to add for example an email to your workspace, you just have to open an email, then our plugin AHAU 260 DEVproduct, choose the workspace and then click on the top (in orange) and it will be add. 
it will be added to it.
2. To add tasks
To add tasks to your workspace, you just have to click on this button, and choose the task you want or many tasks.
3. Add documents
1. First you open the workspace.
2. Then the workspace will open on that space that is selected.
3. Go to the end of the list, choose documents, click on the plus button
and choose the document you want to add to this workspace.
4. Rest of the items
Its the same process for the rest of the items, has contacts, checklists, bookmarks.