I have made things just like that. They are transformers for switching power supplies. They typically are run with 100 kHz square waves.
The bobbin has a bunch of pins that wires are soldered to. For now, they twist the wires on the pins to hold them in place. The narrow white tape creates a high-voltage barrier between the primary power line winding and the secondary winding that you might touch. The winding is bifilar, meaning that two wires are run in parallel to improve the current carrying capacity without adversely affecting the other parameters.
It takes a lot longer for me to make one of these, but I've only made a dozen at a time. I have paid people like her to make hundreds for me.