To place data into this section, you can use the __DATA macro, thus:
__DATA(RAM2) char data_buffer ; // create an initialised 1k buffer in RAM2
Or the __BSS macro:
__BSS(RAM2) char bss_buffer ; // create a zero-init buffer in RAM2
Of course, if you do not place any data into these additional areas, then the linker does not create anything in those areas.
In order to initialize additional RAM banks, the managed linker script mechanism will create a "Global Section Table" in your image, directly after the vector table. This contains the addresses and lengths of each of the data and bss sections, so that the startup code can then initialize them.
The LPCXpresso generated startup code will then initialization of multiple regions by entering a loop reading this global section table, and calling a subroutine to carry out the initialization of each region it finds in the Global Section Table.