What is the 35 dwellings per hectare rule near stations?

Net developable area, not site area

This is the detail that changes the arithmetic. The minimum bites on the net developable area, which excludes the spine road, attenuation basins and open space. On a real layout that can be a large fraction of the site, so the density you have to hit across the buildable part is easier to reach than the headline figure suggests.

What comes out of the denominator is where the argument usually is.

Only the part within walking distance

Where only part of the site falls within reasonable walking distance of the station, the glossary is explicit that the density requirement applies only to that part. A long site running away from a station is not required to be uniformly dense.

The trap

Being near a good station is what opens the route, and it is also what sets the minimum. A generous, low-density scheme on a station-adjacent site can clear the principle of development and still have to be refused for inefficient use of land.

The escape is narrow: you must be below the major threshold and able to demonstrate that meeting the standard is inappropriate or not possible. Preferring larger plots is not enough on its own.