Currently, the only way to enter data is individually. If your current SketchUp selection is multiple components, in Estimator, there will be a drop-down box in Components and all of the components, individual, will be available to select – BUT you can only enter data one at a time. So, currently, the answer is no.
What we are working on (and I have no assurance it will be done and when, but it is in-process) – you will have ONE CSV file that you will be able to edit at one time. For example, LUMBER, you will be able to open the file and see your database lumber materials – add Vendor to any and all of them – edit their prices, etc. as if in a spreadsheet – save and then it will be there. This new update will take care of what you are asking, I just have no idea when I will receive it. I will certainly keep you posted.