Hi Jana,
To delete a row, right click on the menu on left of first column of the repeating table and select delete (as shown in screenshot below)
consider a repeating with fields (field_1,field_2,field_3,field_4)
To make sure that all fields are required if any of the field is not blank apply rule on field_1 as :

apply rule on rest of the fields(field_2,field_3,field_4) as :

Hope this helps.
Regards
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Hammad Naeem
Precisely Software Inc.
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