Terminal Block Strip Electrical Block Connector 3A 5A 10 Amp /36 Wire Connectors min and max current limit?
Those ratings indicate that the smallest terminal block can safely carry up to 3 Amps on each terminal, the middle one can handle up to 5 Amps, and the largest, up to 10 Amps.

The terminals will over-heat if they are asked to carry more than the rated current.