Nick,
If these were very small when planted, they will increse in size. Perhaps some will split later. They are to be harvested when the tops dry.
Shallots are best planted in the fall in many planting zones.
Planting some of the largest should give you a nest of smaller ones when next harvested.

Here is a link that might be useful: Shallots

Shallots is weird.
The classic shallot is mild, sweet, and a cross in flavor between a garlic and an onion. The best I have experienced have an almost rose like additional flavor. Most shallots sold in the store, form rings like a classic cepa onion. Some shallots do not always grow concentric rings. They can grow a leaf beside another leaf, and eventually each new leaf grows a bulb.
Most shallots divide when the bulb leaves dormancy. These produce bunches of leaves in the center of the bulb. The bulb is digested by the young plants and the remainder rots away leaving a bundle of small plants. These shallots usually alternate size each year. You plant a big bulb, you get a bunch of tiny bulbs at the end of the season. You plant a tiny bulb you get a big bulb.
Some shallots produce small bulbs beside large bulbs. Some shallots flower every year, others flower once in a lifetime or less.
Some shallots try to do all of the above. Go figure.
Daylength is also very important. The bulb is the method of storing what the plant needs to survive the dormant season. The way that onions tell what time of year it is, is by measuring the length of the day and comparing it with the temperature. (Actually they measure the length of the night, but why quibble.) If your latitude is not right for your onion, it won't usually bulb. So it is entirely possible for you to get a shallot that will never, ever make a plump bulb for you. As a result of this, just about every area has a plant they call shallots, that works for them. They don't usually know what type it is or where it came from. They just call it shallots.
Here is the fun part, any purist will insist that the shallot you have isn't a true shallot. Or it isn't the right shallot, or that nothing is a true shallot. Or that theirs is a true shallot.
In a lot of areas shallot means dividing onion.
In botany the term for dividing onion is bunching onion.
In agriculture the term bunching onion means you can grow it close together and sell it as a green onion.
In other words, the language to describe these things is all mixed up.

When you eat a shallot as a green onion, it may or may not have the garlic flavor the bulb may have. Even if a shallot never bulbs, it may still grow and spread. It may still be a tasty perpetual delight in your garden.