You can achieve this result with actual modelling as well, which is good if you want to have the capital and the pillar all one piece. The basic concept is the extruding and scaling of a circle:
To make the inset parts of the pillar, select the lower face loop (Alt+RMB in face select mode), and then Select > Checker Deselect. Now simply extrude and scale inwards.
This is fairly easy to edit as you can just Alt+RMB to select an edge loop, and then scale it again to change that edge loop's shape. You can also add another edge loop at any point using Ctrl+R+LMB (x2). You may also find it useful to be able to crease edges using Shift+E if you add a subdivision surface modifier.
Following Reference Wire:
While this might be a harder/less efficient way to do this (depending on level of experience), it has the benefit of already being a mesh, and being able to incorporate the rest of the pillar in one piece. You can move the loops in extremely precise (to the fourth decimal place) increments using numerical inputs, the same for scaling. Also you will not get any weird topology artifacts from exporting like you would with a curve object.