When you are creating a schedule you see question marks instead of the objects information.
You can update this information by selecting all the same objects in the drawing and then from the properties tool palette on the Extended Data tab click on the icon called "Add Property Sets". In the lower left corner.
or you can select the schedule and right click to select "Add All Property Sets" and this will update all the objects you have selected for the schedule.
You will see a line through the schedule letting you know you need to update it. This can be done by selecting the schedule and right clicking to select "Update Schedule Table" or from the ribbon you can select on "Update".