If tasks are enabled then in the bottom left hand window you will see 'Current Tasks'. If you created the workspace by selecting a task then this task will already be included.
Each task listed within Current Tasks is a local changeset - so you can perform the same operations like submitting it to the server. To stop working on a task within the workspace right-click the task and select 'Delete'. This will remove it from the Current Tasks without deleting the actual task.
You can work on a new task by right-clicking Current Tasks and selecting 'Work On Task'. This will launch the Select Tasks dialog.
My Tasks shows all tasks which are assigned to you in the same version or feature which the workspace is based on. Team Tasks shows all tasks in the same version or feature which are not assigned to you. If you select a team task then the task will be assigned to you.
Create New Task will create a new task in the version or feature which the workspace is based on. The new task will be assigned to you and appear in the My Tasks list.
Select one or more tasks and press OK to add them to the Current Tasks.
Work On Task creates a new local changeset for each task. This is great where each task requires a separate submit. If you want to submit multiple tasks in the same changeset then create a current task for one of the tasks with the Work on Task menu. Open the properties for this local changset and you will see a Tasks tab.
The checked tasks are associated with this local changeset. You can therefore check all the tasks you want to submit.