Wirespeed means that logic such as access-lists are computed in circuitry
Non-blocking means that if sum of all bandwidth on all switchports is less than or equal to the bandwidth of the backplane of a switch then the switch is none blocking...i.e. the backplane is not a bottleneck if all switch ports are in use and being fully utilised.
32 Gbps is the bandwidth capabilities of the switch data bus
256 Gbps switch fabric is a module that provide 256 Gbps of available bandwidth to switch fabric enabled modules only. Not switch fabric enabled module have to traverse the 32 Gbps data bus to get to the fabric module.
Rgds
Paddy