1. Roebury Picnic Blanket - Portable Outdoor Mat Folds into Tote Bag - Water-Resistant, Sandproof - Large Rug Perfect for Camping, Beach, Festivals, Kids & Babies (Wave Design) (Click Link to Check Price on Amazon)
Editor's Rating : 8.9 out of 10
Large 55" x 70" oversize size blanket fits the whole familyDurable water resistant backing and padding for use on grass , sand or outdoors

2. Datechip Waterproof Picnic Blanket Foldable Portable Sand Proof Large Mat for Outdoor Beach Camping Hiking Travelling -Green (Click Link to Check Price on Amazon)
Editor's Rating : 9.5 out of 10
LARGE SIZE & PORTABLE -- Folds out to 57 x 78inch, suitable for the whole family to enjoy holiday! Folds up to 12 x 9 x 4inch, easy to be carried around with the attached strap.STURDY & DURABLE -- Made of three layers of composite material (Waterproof PVC+ Pearl cotton + High quality polar fleece), soft and comfortable to sit on.

3. XL Plush Fleece Outdoor Stadium Waterproof Blanket (Click Link to Check Price on Amazon)
Editor's Rating : 9.4 out of 10
72" x 58" A perfect size for two adultsWaterproof outer shell and soft fleece interior will keep you comfy, warm and dry

4. JJ Cole Outdoor Blanket,Gray/Green, 5' x 5' (Click Link to Check Price on Amazon)
Editor's Rating : 9 out of 10
5 ft x 5 ft when openedWater-resistant material perfect for any outing

5. Yodo Soft Compact Outdoor Water-Resistant Picnic Blanket Tote,Beige Stripe (Click Link to Check Price on Amazon)
Editor's Rating : 9.1 out of 10
Blanket measures 59 x 53 inches when open, and folds to a compact tote 12.5 x 8 x 4 inches for easy carryWater-proof backing prevents ground moisture from penetrating - no more 'wet bottom' picnics