Dear respected Shravyashree Shetty,
Good day! Thank you for posting to Microsoft Community. We are happy to help you.
As per your description, using Power Automate "List rows present in a table" action, the Power Automate can handle up to 256 rows per request by default. The max limit of rows which we can retrieve is limited by default at 256. In order to increase this limit and retrieve more rows we can enable the pagination and then retrieve the next batch in Power Automate(for your reference: 256 rows limit - Power Platform Community).
Appreciate your patience and understanding and thank you for your time and cooperation.
Sincerely,
Waqas Muhammad