The connector will run in batch - it will be VERY Easy for you to go over the limit - especially if you want to bring back activities - which I am not sure it can do?
For anyone interested in Tableau and Marketo, I'd like to share that our new version of the connector is available for feedback. We'd love to hear if it works for you and how we can improve it. The new version supports all data it is possible to retrieve from Marketo that customers have told us they'd like to visualize in Tableau.
As Neil Robertson-Ravo notes it is very easy to exceed your API limit unless you have increased it, so please be aware of this if you decide to try the new connector. Marketo has been improving this situation by releasing a bulk API that reduces the number of API calls but we've not yet had the change to adopt it.
Senior Product Manager