Possible Clues:

• Protection on board secured by stablemate?
• Mother brought in slab on which a plate rests
• Competent scholar embraced by non-drinker takes cover
• Shoddy work includes misplaced blame for part of setting
• Protective pad placed beneath plates at meals
• Pill mother swallowed for protection at meal
• Metal tab (anag)
• Sweet singer turning up to plug rubbish — this is flat
• Protector from hot plates
• Surface protector