Look at it like this, take one seat has 34% voted for Tories and 33% voted for LD, Tories will get the seat, more often than not each seat (battleground seats mostly) is fought between only 2 main parties (usually Labour vs Tories but sometimes Tory/Labour vs LD) but often in battleground seats where the breakthrough occurs its usually by a few hundred votes.
Usually in an election the entire result of who gets a majority relies on low majority battleground seats. The problem is though, the fate of the country relies on a few hundred votes in the battleground seats which is insane as often over half the country doesn't get a say in anyway about how the country is run.
So we get Tories with 37-38% of the vote getting over 300 seats and yet LD with 23% of the vote only get 55 seats.
Unless you make some miracle breakthrough, a third party has a very very hard time pushing through to getting any decent amount of seats in parliament. this is why FPTP is rather silly as ultimately you have 37-38% of the country running the country and the rest have no say at all.
as others have said, thats it game over, Conservative would get an overall majority, barring a revolt of backbenchers they can push through any policies they like because they have a majority in seats.