Note: you must have completed A Good Deed/Wintersday Cheer and heard the subsequent 6 dialogs between Gwen and Thackery in the HoM in Eotn to gain access to this "quest"
Picnic items (Thackeray's scavenger hunt)
In exchange for providing him with items that he can use for his planned picnic, he will reward you with a Paper Wrapped Parcel (for perfect items) or a Sack of Random Junk (for merely suitable items). Also, The gift limits are per character, not per account. Each character will end up with a minimum of 4 items from Thackeray or a maximum of 4 Paper Wrapped Parcels and 12 Sacks of Random Junk.
Note: That you can get up to 3 more junk bags by offering additional sets of candles.
Primary item A=Set of Votive Candles (exchange for 3 Honeycombs from Necromancer Munne (in Sardelac Sanitarium)
Primary item B=Birthday Cupcake (Drops during Birthday Celebrations)
-OR-
Any combination of 3: Chocolate Bunny, Crème Brûlée, Pumpkin Cookie, Red Bean Cake or Slice of Pumpkin Pie
Primary item C=Drake Kabob (In exchange for 1 Chunk of Drake Flesh from Chef Lonbahn (in Kamadan)
-OR-
Any combination of 3: Bowl of Skalefin Soup, Chunk of Drake Flesh, Herring, Pahnai Salad or Truffle
Primary item D=Hard Apple Cider (Drops during Special Treats Weekend in November)
-OR-
Any combination of 3: Rice Wine, Vabbian Wine, Dwarven Ale, Eggnog, Hunters Ale or Shamrock Ale
The easiest and fastest way to do this is to use these items;
>3 Red Bean Cakes (expensive sweet is always available for sale at Factions merchants)
>3 orders of Pahnai Salad (made from easy-to-farm Iboga Petals) or 3 Bowls of Skalefin Soup (made from easy-to-farm Nightfall Skale Fins)
>3 Dwarven Ales (can be purchased from Embark Beach merchants, among other locations)
>6 Votive Candles (in exchange for 3 Honeycombs from Necromancer Munne in Sardelac Sanitarium after speaking to Keiran about candles).
NOTES
You can save time by collecting items before speaking to Thackeray in Ice Cliffs Chasms. For three of the request types, you must offer a minimum of a single perfect item or three suitable items; you must, however, bring him Votive Candles, as that item has no acceptable substitutes.
After gathering the last item, speak to Thackeray one last time to hear him say that there is one last component: "The hardest part. I still need to get the girl." Then, return to the HoM so he can speak to Gwen again, completing this task.