Saudi Arabi today voiced clear objections to the European declaration on the Middle East issued last week in Venice, calling it "vague" and insufficient as a basis for settlement of the Palestinian problem. "

But the criticism did little to spoil Saudi King Khalid's first state visit to West Germany, which ended today in a general air of excellent German-Saudi relations and the promise of expanded and the promise of expanded ties between Europe's most powerful economy and the oil-rich kingdom.

For Bonn, it was oil. German officials looked pleased to get assurances that Saudi oil supplies, which account for 24 percent of West Germany's total, would run smoothly.

For the Saudis, it was technical expertise and military assistance. On the Saudi shopping list is German engineering assistance and sizable orders for road construction and a telephone network.

In addition, Bonn defense officials offered this week to help train the Saudis' expanding armed forces by providing facilities and instruction here. However, a Bonn Defense Ministry spokesman ruled out the possibility of German military advisers being sent to Saudi Arabia, leaving that to the British who are already there.

The Soviet invasion of Afghanistan and the unrest in Iran has heightened European concern about the Persian Gulf. Doubtful that President Carter's Camp David inspired Egyptian-Israeli talks can solve the Palestinian problem, the Europeans have felt compelled to step up their own Middle East efforts.

This was behind the European Community's declaration last week, which formally recognized the Palestinians' right to self-determination and urged that the Palestine Liberation Organization be somehow associated with the peace process.

But Saudi Foreign Minister Prince Saud said that "we thought that it fell short of a statement that could be implemented as a basis for a settlement."