Here is a soliloquy from Macbeth page 54-
" Might be the be-all and the end-all here,/
But here, upon this bank and shoal of time,/
We'd jump the life to come."
This quote means if Macbeth kills Duncan the king he will suffer after for ever apposed to regular life as a king it'd be good, but when he dies he will be damned for taking a life, forever. Soliloquy is when a character talks to one self and in this case Macbeth is trying to make a decision .