Most modern Android tablets and phones can use USB peripherals from memory sticks to keyboards to USB microphones or to multiple inputs using a USB audio interface.
The technology is called USB On-The-Go, and is often abbreviated to USB OTG or just OTG.
All you need is a simple cable that costs just a few dollars. This example has 3 USB inputs and an additional input for your charger.
You may have to use a powered USB hub as well if your choice of peripherals turns out to be too power hungry for your tablet.
There a a few OTG checkers apps that you can download from the Google play store for free to check your tablet or phone BEFORE buying an OTG cable but is your device is recent then it should work just fine.
Once you have your cable then you can do a quick check using a USB stick or a computer keyboard and confirm that the basics work.
Next step is to install a recording app such as WaveEditor by Sound-Base Audio and start experimenting with recording yourself.
This is covered in parts 2 using USB microphones (coming soon) and part 3 using audio interfaces (coming soon). Part 4 will be on using USB MIDI keyboards with your tablet.
You can also read more about USB_On-The-Go on Wikipedia.
Onwards to part 2… (coming soon)