I've had this Ficus benjamina for some time. It recently grew several small round objects on its stem. I have no idea if these are indeed pods/seeds or something else (see attached image).
If they are seeds, what do I do next?
Yes, they are seed pods. As Ficus benjamina is a member of the Fig family they are figs and are edible when ripe. (Notice: I did not say tasty and I would not eat them)
The ficus family is pollinated by species specific tiny wasps which are unlikely to have access to the figs. So you will not get viable seed from the figs.
They are likely to increase in size by one third and turn yellow. Ficus nitida figs turn a red orange.
Keep up the humidity and do not move the plant if you want to keep them.