This article explains how to view more than 50 Jira issues in a JSON macro using maxResults.
In the Advanced Table for Confluence app, Jira Rest API displays 50 issues by default. In order to show more than 50 issues, you need to use &maxResults in the URL.
Please find the example below where the maxResults for the URL is given as 100:
Use &maxResults in the URL of JSON data field to retrieve the results. Please check the screenshot below for reference:
In this example, maxResults results in 100 issues. It previews 100 issues of the given project. You can use any number greater than 50 to show those many records through Jira Rest API.
The maximum limit for maxResults is 1000.