That's odd, I had no idea the EPA even presented a spec like that. It must be a difference in how they estimate it.
The BMW comparison is interesting as the performance numbers are similar. The 3 series heft vs a civic is largely due to the engine and drivetrain choices. Its much easier to optimize weight on a low powered FWD car.
Regardless, the Accord dwarfs it and supports the above point that the Model 3 is a heavy car, and the BMW 3 series is heavy because it was built to have a premium feel as a design priority, not because it is ICE.