These are lubricating syringes (not inoculation syringes) for use in helping you maintain your sewing machine. Using syringes helps you place the kerosene or oil where you want it and control how much you dispense. Syringes come empty ready for you to fill.
Nova's students use these in her workshops.
The large syringe is typically used for kerosene to clean the mechanical workings of the machine - more kerosene is typically needed than sewing machine oil. The smaller syringe is typically used for sewing machine oil.
Kerosene and oil deteriorate the rubber stopper in the syringe over time, so they will need to be replaced periodically. Nova has found that they last the longest when left filled with either kerosene or oil.