How to Query Which Table Is Inserted Mostly In SQL Server?
To know mostly inserted table you can simply retrieve number of rows/records in the table.

You can use following query to find it. Mostly inserted tables will be displayed on top of the records.

SELECT
   o.Name TableName,SUM(ps.row_count) Total_Rows
FROM
            sys.dm_db_partition_stats ps
inner join  sys.objects o
on ps.object_id=o.object_id
WHERE o.type='U'
GROUP BY
    o.Name
ORDER BY 2 DESC


Edit:1

As you described you requirement in comments, "you need find mostly inserted tables between a date range. It can be done using several method.


Using AFTER TRIGGER on the tables.
Using IDENTITY type column along with a column which records insert date &amp; time (like Amina commented).
Using CDC you can record date &amp; time of every changes in the table.
enabling Temporal Table (SQL Server 2016 +) feature on a table to record every changes.
Track Data Changes (SQL Server 2017)


Thanks!