Why did the Zionist accept the partition plan in 1947 and why did the Palestinians reject it Were the Zionist really trying to be peaceful or was there a lot more to it than that ?

It was the later. While publicly the Zionist Yishuv accepted the partition plan, it did so as a temporary tactic only. In private, they rejected any idea of partition and quite candidly admitted that partition would be a means to establish a strong army to take over the rest of Palestine.
While addressing the Zionist Executive, Ben Gurion emphasized that any acceptance of partition would be tactical and temporary:

“After the formation of a large army in the wake of the establishment of the state, we will abolish partition and expand to the whole of Palestine.”