Are these statements used inside of proc code or outside?
If the later, then I guess that developer who sent you this code just scripted something in SSMS and used it as his template for creating stored procedures.
If these statements are inside of proc, than probably they required to achieve some sort of functionality.
I guess you know what BEGIN TRANSACTION and COMMIT are for?
Each of the listed SET commands changes specific connection setting, You can refer to BoL for details.
"The only true wisdom is in knowing you know nothing"
"O skol'ko nam otkrytiy chudnyh prevnosit microsofta duh!":-D
(So many miracle inventions provided by MS to us...)How to post your question to get the best and quick help