How many trees does a Random Forest need?
By other posts and this one seems what you don't have a clear intuition of the n_estimators of the random forest. 

I am going to assume that you are referring to the n_estimators (from this other question). n_estimators is the number of trees that your 'forest' has. Not the depth of your tree. That is another parameter.

If you are referring to max_depth = 100, 100 splits it can be a lot. Feel free to plot one tree and see what it is doing. see this link

The number of rows and columns is not necessarily important, what is important is the complexity of your problem.