Translation:He is arranging fruit
Is he lining them up or putting them in a circle? By colour or by taste? Maybe by texture?
She actually has a very profitable fruit stall in the market, partly due to the impressive way she arranges the fruit, however she's also a talented artist, her still life compositions are highly sought after and break new ground in this form... :)
One fruit is "tunda".
If you say "jitunda" it would probably be an augmentative noun, meaning "large fruit", but I haven't seen it being used, so I'm not sure abut it. If I'm correct about that, "jitunda" would have the plural "majitunda" and not "matunda".