A 5k general exp is an item in Evony TKR (The King's Return).
The description of 5K General EXP in Evony TKR says:
Grants your General 5,000 EXP.
5K General EXP is known to potentially be obtainable from opening Lv10 Boss Monster Chest. The links for each item are below:
Note: This list may be incomplete.