I'd better be off.	Can't complain.	
What have you been up to?	Haven't seen him.	
Fancy a snack?	I'm a bit peckish myself.	
How's life?	Just gone half past.	
Got the time?	Me too. I'm parched.	
Mind if I sit here?	Nothing. I'm just a bit tired.	
Have you got a minute?	Oh, this and that.	
I'd better make a move.	See you then.	
I'm absolutely starving!	Sure, go ahead.	
I'm dying for a drink.	Sure. What is it?	
Tom about today?	Why? What have you been doing?	
What's up?	Yeah, time I pushed off too.	
I'm absolutely knackered!	Yeah, why not?	

Answers and notes	

Beginning	Notes	Ending	Notes	
I'd better be off.	I had better... 'be off' means 'leave' here.	See you then.	An informal way of saying goodbye.	
What have you been up to?	What have you been doing?	Oh, this and that.	Nothing important or interesting.	
Fancy a snack?	'Do you fancy...' is an informal way of saying. 'Would you like...	Yeah, why not?	Yeah is informal for yes. The phrase is an informal way of accepting a suggestion.	
How's life?	An informal way of saying, 'How are you?'	Can't complain.	Not bad.	
Got the time?	Have you got the time i.e. Do you know what the time is?	Just gone half past.	It has just gone half past (two, three etc.)	
Mind if I sit here?	Do you mind if I... 
A common way to ask permission.	Sure, go ahead.	A common way to give permission	
Have you got a minute?	Have you got some time so that I can ask you a question, discuss something etc	Sure. What is it?	Sure - yes.	
I'd better make a move.	I had better... 'make a move' means 'leave' here.	Yeah, time I pushed off too.	 'push off' is another formal way of saying 'leave'.	
I'm absolutely starving!	Starving - absolute adjective for hungry.	I'm a bit peckish myself.	Peckish - slightly hungry	
I'm dying for a drink.	I'm dying for something.
i.e. I want it very much.	Me too. I'm parched.	Parched - very dry; very thirsty	
Tom about today?	Is Tom about... - is Tom around, in the office, in this place etc?	Haven't seen him.	I haven't seen him	
What's up?	What is wrong?	Nothing. I'm just a bit tired.		
I'm absolutely knackered!	Knackered - absolute adjective. Very tired.	Why? What have you been doing?