Pads are normal MIDI "buttons", which can case Notes / CC. So with any other such controls, options are:
1. MIDI Keyboard shortcuts. Configured at the same place as computer keyboard shortcuts. Do not forget to define MIDI "Shift" and "Enable" flag. The only caveat - you will have to press 2 pads for any action (Shift + <somthing>). Assign Shift to something you do not use for normal MIDI, I mean C4 is a bad idea.
2. "ACT MIDI" Control surface plug-in. You can configure 8 buttons and assign "General" subset of keyboard shortcuts there. Shift is not required, so you will need press just one pad to perform the action. But in this case all pads should not intersect with normal keys. This time that is easy to achieve if you configure different MIDI channel for pads. If pads are Notes, "Note off" will leak into normal MIDI input, assign CC to pads to avoid that.
3. AZ Controller (see signature). You can assign almost any possible for Control surfaces reaction, including combinations of them. You can also get rig of Automap configuring the rest. But it can take some time till you understand how...