@Shashi_Mulugu Thanks for your response. However, this is not working for me.
If I overwrite cq_dialog definition of Page component then its working. Following is what I added in dialog definition.
<basic jcr:primaryType="nt:unstructured">
<items jcr:primaryType="nt:unstructured">
<column jcr:primaryType="nt:unstructured">
<items jcr:primaryType="nt:unstructured">
<tags
jcr:primaryType="nt:unstructured"
allowBulkEdit="{Boolean}true"/>
</items>
</column>
</items>
</basic>
Thanks,
Raj