Hey, there - Retools support here happy to help! 
So technically this query updates a single record according to your action type: "update an existing record". In order to get it to update for several changes, you will need to create a separate javascript function and loop through the recordUpdates and trigger this write_alterwood_table query with the additional scope of each element that has been updated passed in.
Here's an example of what that Javascript loop might look like: http://community.retool.com/t/how-to-run-a-rest-api-query-for-each-item-in-an-array-and-return-all-results-together/2352