Hi,
This field is not editable for the Admin context (which is the one it will show when you click on the device itself). The reason for that is that this configuration is taken from the switch itself.
For the other contexts, you will get a "select" button next to the field allowing you to choose which vlans (from the ones shown in the Admin contex) to associate with this new context.
For your reference, if you are trying to configure the vlans assigned to a module from the switch, you would need to use commands like the ones below:
svclc module 4 vlan-group 2,41
svclc vlan-group 2 2,6,32
svclc vlan-group 41 35-39,41-43,1109
I hope this helps
Daniel