The festival based in Wales will see England U18s play Scotland at Ystrad Mynach (31 March), Italy at Cardiff Arms Park (4 April) and France at the same venue on April 8.
England U18s have played three games this season, losing to France (27-5) before sealing victories against Scotland (64-0) and Wales (42-14), with Martin the only of the pair to be involved in the warm up matches.
In recent weeks, Lavin has played back-to-back matches for the Tigers Development XV in this season's Premiership Rugby A League competition following the conclusion of this season's Academy U18 League.
Both players were members of the successful Academy side which went through the U18 League season undefeated, including a 43-21 Grand Final victory over Gloucester at Allianz Park.
Tigers lock Cameron Jordan, who also featured for England earlier this month, was not considered for selection due to age.
When asked about he felt after receiving the call-up to a national squad for the first time, the young Tigers back-rower admitted to instant pride.
"It was a really proud moment, I feel really honoured," said Lavin.
"It's a special moment for me ... it's nice to see the hard work paying off and feeling like you're getting a reward for it."
Lavin's selection, after missing out on the initial squad announced last month, comes at the end of a season which has included not only Academy Grand Final success and A League appearances but also a senior debut for the club, when selected to feature in the Anglo-Welsh Cup against Wasps in Coventry.
Dave Wilks, Leicester's Academy Manager, told LeicesterTigers.com the opportunity was well deserved.
"It's a good opportunity for him to go and prove himself at that level and he certainly deserves the chance to show what he can do," Wilks said.
England U18s squad
Forwards: Alfie Barbeary - Wasps (Bloxham School), Jack Bartlett - Gloucester Rugby, Ben Donnell - London Irish (Peter Symonds College), Rob Farrar - Newcastle Falcons (Sedbergh School), Cal Ford - Sale Sharks (Sandbach School), Lewis Holsey - Worcester Warriors (Solihull School), Henri Lavin - Leicester Tigers (Wyggeston & Queen Elizabeth), Ted Leatherbarrow - Sale Sharks (Kirkham Grammar School), Samson Ma'asi - Northampton Saints (St Josephs), George Martin - Leicester Tigers (Brooksby Melton College), Will Montgomery - Newcastle Falcons (Kirkbie Kendal School), Bevan Rodd - Sale Sharks (Sedbergh School), JJ Tonks - Gloucester Rugby (Hartpury College), Rus Tuima - Exeter Chiefs (Exeter College)
Backs: Harry Barlow - Harlequins (Cranleigh School), George Barton - Gloucester Rugby (Dean Close School), Blake Boyland - Bristol Rugby (SGS College), Connor Doherty - Sale Sharks (Kirkham Grammar School), Reece Dunn - Gloucester Rugby (St Peter's High School, Josh Hodge - Newcastle Falcons (Sedbergh School), Jacob Morris - Gloucester Rugby (Hartpury College), Callum Pascoe - Newcastle Falcons (Gosforth Academy), Jack Reeves - Gloucester Rugby (Hartpury College), Will Simonds - Wasps (The Henley College), Ollie Sleightholme - Northampton Saints (Northampton School for Boys), Manu Vunipola - Saracens (Harrow)