Size of decision tree and depth of decision tree
The depth of a decision tree is the length of the longest path from a root to a leaf.

The size of a decision tree is the number of nodes in the tree.

Note that if each node of the decision tree makes a binary decision, the size can be as large as $2^{d+1}-1$, where $d$ is the depth.  If some nodes have more than 2 children (e.g., they make a ternary decision instead of a binary decision), then the size can be even larger.  So, a size of 7650 is not unreasonable, if some nodes make binary decisions and some make ternary or multi-way decisions.