The Parliament of India is a deliberative body with various functions. It serves as a platform for representing the people`s interests and concerns, but it also has other important responsibilities.

Option 1, ventilating the grievances of the people, is a function of the Parliament. It provides a platform for citizens to raise their concerns and grievances.

Option 2, executing major policy decisions, is not a function of the Parliament. The execution of policies is primarily the responsibility of the executive branch of the government, headed by the Prime Minister and his/her cabinet. The Parliament`s role is to scrutinize and debate policies, but the actual implementation is not within its purview.

Option 3, holding the government accountable for its actions and expenditure, is a crucial function of the Parliament. It ensures that the government is answerable for its decisions and expenditures.

Option 4, amending the Constitution, is another essential function of the Parliament. The Parliament has the authority to make changes to the Constitution, subject to certain procedural requirements.

Therefore, the correct answer is option 2, as executing major policy decisions is not a function of the Parliament of India.