It'll certainly be possible to use the API to export data into an Excel table - Creating a CSV file is probably one of the easiest ways to do this although an alternative is to output an HTML < Table > then copy and paste it into Excel.

I've found steemchiller's API easy to work with - just 2 lines of code to get me started...

    $jsonAuthorPosts = file_get_contents($getAuthorsPostsURL);
    $decodedjsonAuthorPosts = json_decode($jsonAuthorPosts,true); // Convert the returned JSON object into an Array

...and then it's a case of working with key / value pairs and arrays to manipulate the data.

You could even use it to output the entire post contents which is something that I used to do and add a custom introduction to. Although this wasn't using the API, my intention at the time was to automate it which I would be able to do now with my acquired knowledge (apart from the posting it bit which I haven't learnt yet).