MS Excel makes it painfully easy, but you do need a copy of this.
I think your best bet though would be visiting drive.google.com and creating a new spreadsheet (click on the red "create" button)
Next, paste your data into the sheet then from the "Data" Menu, select sort and you are off to the races.
As Jim said MS Exel is the way to go but if you don't have MS Office/MS Exel, you can download the free Open Office software and use the spreadsheet included.
Using your example, you can paste all of those lines into Microsoft Excel, and then sort by the number column ("B")
If you don't have excel to do as suggested in the other answers, try Google Docs
Is there any site where I can place a huge amount of text along with numbers and it puts in in ranking order for example
London 20
Manchester 30
Birmingham 15
Liverpool 20
So putting it in order by numbers
Birmingham 15
London 20
Liverpool 20
Manchester 30
