The answer is:
Egg.
Eagle:
Eagle -> golden eagle -> golden egg -> egg. (First solved by: @puzzledPig)
Final:
Final -> cup final -> egg cup -> egg. (First solved by: @Statman)
Flag:
Flag -> white flag -> egg white -> egg. (First solved by: @puzzledPig)
Hands:
Hands -> hands-on -> egg on -> egg. (First solved by: @puzzledPig / @Paige Meinke)
Hard:
Hard -> hardboiled -> boiled egg -> egg.
Left:
Left -> leftover -> over-egg -> egg. (First solved by: @puzzledPig)
Medicine:
Medicine -> bad medicine -> bad egg -> egg.
Morning:
Morning -> good morning -> good egg -> egg. (First solved by: @puzzledPig)
Pop:
Pop -> Pop Tart -> egg tart -> egg.
Rat's:
Rat's -> Rat's nest -> nest egg -> egg.
Shock:
Shock -> shell shock -> eggshell -> egg. (With thanks to @Statman for a comment hinting at this answer.)
Sunday:
Sunday -> Easter Sunday -> Easter egg -> egg. (Here's the most explicit "seasonal" part.)
And finally, as the OP had to point out to everybody, the form of the table looks roughly like:
an egg carton with a dozen "eggs".