Lunedi Chiuso = Mondays closed. Notice that there is an accent on the end of Lunedi. This means that you need to put the stress or emphasis on the end of the word.
da Martedi al Venerdi 9.00/19.00 = from Tuesday to Friday 9am to 7pm.
Sabato orario continuato 9.00/16.00 = Saturday open all day from 9am to 4pm.
Remember the term orario continuato, you often see it with supermarkets. Most smaller shops shut from 12.30 to 3.30pm in Italy but stay open until about 7 or 7.30pm. But Saturdays they often shut a little earlier.
Don't be tempted to pronounce Chiuso as Chooso. The ch combination in Italian represents a k-sound. The Italian alphabet does not include k. That is why you see chilo written instead of kilo (though international signage means that the word kilometre is spelt with a k rather than the Italian chilometro.
Listen to the word chiuso here. It sounds a bit robotic but you get the sound.