You can exclude entire table using below way from magento 1 to magento 2 migration,
Edit your map.xml file into your migration directory from,
vendor/magento/data-migration-tool/etc/{Migrate-version}/{Old-magento1-version}/map.xml
Now add below content in source -> document_rules node,
<source>
<document_rules>
<ignore>
<document>custom_tablename</document>
</ignore>
<document_rules>
<source>
Replace custom_tablename with your table name and run migration command.
if issue solved, Click Kudos/Accept as Solutions.