Eurorail travel time

There are no "Eurorail" trains. Eurail sells passes for the European rail companies, which run the trains. IMO, the best place for schedules all over Europe is the German Rail webpage. You are going to Barcelona by air, Venice on the cruise ship, then back to Barcelona where you will fly out, and you want to know what to do with you luggage while you are traveling by train from Venice to Barcelona? Take it with you. Unless you don't want to miss Cinque Terre, book an open jaws flight into Barcelona and out of Venice. It shouldn't cost much more than the average of RT to Barcelona and Venice.

Use an open jaw makes more sense economically and convenience wise. Venice back to Barcelona is a long back track and a waste of good travel time. And consider your luggage carefully. Just because it is a cruise it does not mean that you have to have a lot of extra luggage. We normally travel with two carryon size, backpack style of luggage. When we add in a cruise we only add one carryon size rolling bag for the extra clothing that we need for the cruise. Three bags total.

If you were traveling within Germany, you could check you bags with the Bahn through to your destination, but it would take days for the bags to arrive. I don't know how that works over multiple rail companies.

Everything that has been said in the answers above, I endorse. Looking on the Bahn site, as suggested by Lee, there is only one option for a day train. It means being on the train in La Spezia at 6:05 in the morning, takes 5 changes of train, and takes 16 hours and 5 minutes to Barcelona. Here are the details: La Spezia Centrale Mo, 17.01.11 dep 06:40 IC 658 Intercity Subject to compulsory reservation, Global price, Snacks and beverages available, space for wheelchairs Genova Piazza Principe Mo, 17.01.11 arr 08:15 Transfer time 40 min. Adjust the transfer time Genova Piazza Principe Mo, 17.01.11 dep 08:55 IC 654 Intercity Subject to compulsory reservation, Global price, Snacks and beverages available, space for wheelchairs Ventimiglia Mo, 17.01.11 arr 11:07 Transfer time 40 min. Adjust the transfer time Ventimiglia Mo, 17.01.11 dep 11:47 RE 86174 Regional-Express 2nd class only Nice Ville Mo, 17.01.11 arr 12:36 Transfer time 52 min. Adjust the transfer time Nice Ville Mo, 17.01.11 dep 13:28 4764 Schnellzug Subject to compulsory reservation, Global price Montpellier Saint-Roch Mo, 17.01.11 arr 17:42 Transfer time 1:05 h Adjust the transfer time Montpellier Saint-Roch Mo, 17.01.11 dep 18:47 TGV 6213 TGV Subject to compulsory reservation, Global price, Bar coach Figueras Vilafant Mo, 17.01.11 arr 20:48 Transfer time 15 min. Adjust the transfer time Figueras Vilafant Mo, 17.01.11 dep 21:03 ALS 212 Alaris Subject to compulsory reservation, 2nd class only, Global price, space for wheelchairs
Barcelona Sants Mo, 17.01.11 arr 22:45 If you want to travel overnight its four hours more and as few as one change, in Milan, then the night train.

Just one comment on Nigel's schedule, La Spezia is outside the east end of Cinque Terra, Genova is outside the west end. The IC from La Spezia to Genova stops at only some town (ex. Montorosso, but not Vernazza), so depending on where you are staying you might have to catch a regional train earlier to Genova. (Or plan your last night for somewhere the IC stops.)

Thank you to everyone who responded to my questions about "Eurorail" times between cities. Also, appreciate the heads-up on my spelling.