If I buy an 8 track does it act as an amplifier for the electric guitar? Will I need to buy extra cables to connect it?

Any advice would be great thanks
An 8 track recorder works with line level signals and probably mic xlr inputs.  So it won't function as a power amp and drive speakers.  Will drive a set of headphones if it has a headphone output.  You should also have some kind of preamp between the recorder and the electric guitar.  Like a multifx.
darkoshine Yes you can record guitar with something like that. But I would not use it as an amplifier. Further, if you are recording the electric guitar direct into the recording device, you probably will not end up with a very good sound- a lot of the "magic" of the guitar sound happens with a proper tube amp, mic'd into your recording device.
amp no. i use a Digital 8-Track recorder (Zoom) for recording but it has no capabilites be an amp. it does have built in amp sims which you can use for practice and recording but not as an amp.  mine also has a built in drum machine which is very useful. now if you mean just something to practice with through headphones then yes provided it has amp sims however many don't. 
Just buy any multifx and put it in front of the recorder.  Most recorders will not have amp sim.  And an amp sim is not the same as amplification.  A recorder will provide amplification.  However a recorder may not have the correct input impedance and may affect the signal from the pickups by muting the highs and generally messing up the sound.  Second, a guitar is by most respects designed to be played through a guitar amp or an amp sim to get the desired tone.  A multifx will give you an amp sim.  And a multifx will ensure the guitar tone is not negatively impacted by a input impedance mismatch because it's designed to have a guitar plugged into it.
Quote by darkoshine

doesn't appear to but you may want to check tascam site for further info. as diabilical mentoned the Boss 8-track has them and the Zoom i use does as well (it also has a built in drum machine which is why i got it)  i don't use the built in stuff but rather my Line 6 POD. 
OP, btw these are not built in amplifiers, rather a preamp (you need power amp and speaker to make loud).

I think it might be easier to just buy a processor and a more basic multitracker, although the Zoom R series can be an audio interface to a PC as well as a portable recording solution.

It might be cheaper just to get something like a USB audio interface and a guitar multifx unit though. Like say a used Behringer V-Amp is about $60 and something like a PreSonus Audiobox or Fcusrite Saffire audio interface, if you have a good computer that is.