"The table is full of fish."
Translation:Masa e plină cu pește.
"plină cu" refers to the dominant content of a recipient.
- The bucket is full of paint. = Găleata este plină cu vopsea. --- The paint is the content.
"plină de" usually refers to something scattered over or inside something else.
The bucket is full of paint. = Găleata este plină de vopsea. --- The paint is on the outside surface (paint stains).
The girl is full of paint (on her clothes). = Fata este plină de vopsea (pe haine) --- She's a painter (pictoriță).
The lake is full of water and full of fish. = Lacul este plin cu apă și plin de pește.
The jar is full of yogurt and the yogurt is full of cereals. = Borcanul este plin cu iaurt și iaurtul este plin de cereale.
My previous comment discusses the two translations of "full of", which are "plin(ă) de" and "plin(ă) cu". There's nothing wrong in translating "The table is full of fish." to "Masa e plină cu pește."
"The table is filled with fish." most closely translates to "Masa e umplută cu pește." The difference: "filled" = "umplut(ă)" is a verb (the past participle of "to fill" = "a umple"), while "full" = "plin(ă)" is an adjective. The verb communicates an ongoing action or the fact that the current state is the result of a past action; the adjective communicates a state, though without giving tips about the action that produced it.